Methanol-Promoted Borylation of Arylamines: A Simple and Green Synthetic Method to Arylboronic Acids and Arylboronates

Abstract

A Sandmeyer borylation of arylamines via a SN₂Ar pathway promoted by methanol with sodium nitrite and hydrochloric acid as diazotization agent has been developed, which provide a simple and green synthetic method to arylboronic acids and arylboronates.

Arylboronic acids and boronates are useful building blocks in transition-metal-catalyzed cross-coupling reactions due to their low toxicity and high stability.[1] [2] Generally, the reaction of Grignard or lithium reagents with trialkyl borates are the general synthetic routes.[3] Unfortunately, these methods have low functional-group compatibility because of the strong nucleophilicity of the reagents. The borylation of aryl halides[4] and arenes via C–H activation[5] [6] catalyzed by transition metals have been developed as complementary synthetic methods, which show high functional-group tolerance. In addition, Lewis acid catalyzed electrophilic borylation of electron-rich arenes[7] and an alkoxy base promoted nucleophilic borylation of organic halides[8] provide useful transition-metal-free methods for the preparation of arylboronic acids and boronates, which avoid the high process cost and heavy-metal impurities in the final products.

Aryldiazonium salts are as commonly used as surrogates of aryl halides due to their rich reactivity and diverse transformations.[9] [10] The borylation of arene diazonium salts catalyzed by transition metals[11] or by eosin Y under visible light promoted photoredox catalysis[12] provide an useful approach toward arylboronic ester synthesis (Scheme [1]). Very recently, Wang reported a Sandmeyer-type borylation of arylamines by direct conversion of the amino group of aniline derivatives into the boronate group, which provide an entirely different approach toward arylboronate synthesis.[13] However, it is worth noting that arylboronic acids could not be synthesized with this method,[14] and radical initiators, high temperature, or diazotization agent tert-butyl nitrite (t-BuONO) are necessary for the synthesis of pinacol arylboronates. In continuing our recent work in aryldiazonium salts chemistry,[15] we would like to report a methanol-promoted Sandmeyer borylation of arylamines via a SN₂Ar pathway at room temperature with sodium nitrite and hydrochloric acid as diazotization agent, affording arylboronic acids and esters with high yields.

The most common method for the preparation of diazonium salts is the treatment of aromatic amines with nitrous acid. Usually, the nitrous acid is generated in situ from sodium nitrite and mineral acid.[16] Following this standard method, in our initial investigations, we focused on the direct borylation of 4-toluidine (1a) with sodium nitrite and hydrochloric acid as diazotization agent in the first step, and bis(pinacolato)diboron was utilized as boron source in the second step. The results shown in Table [1] reveal that solvent is vital to this transformation. For nonprotonic solvents, except for ethyl acetate, all gave no reaction within one hour at room temperature (Table [1], entries 1–9). To our delight, when protic solvents such as AcOH and MeOH were used, the yields increased to 50% and 74% under identical conditions, respectively (Table [1], entry 10). Other alcohols except for ethylene glycol and glycerin, ethanol, tert-butanol, 2-methoxyethanol, trifluorethanol, and 2-PrOH, all afforded the borylation products, albeit with low yields (Table [1], entries 13–17). Further optimization was seen by changing the amount of B₂pin₂. The use of one and two equivalents of B₂pin₂ resulted in the borylation product 2a with 38% and 60% yield at room temperature (Table [1], entry 18). However, the addition of four equivalents of B₂pin₂ to the reaction did not improve the isolated yield (Table [1], entry 20).

Table 1 Optimization of the Cross-Coupling of Amine with Bis-(pinacolato)diboron^a

Entry	Solvent	Yield (%)b
1	CH2Cl2	trace
2	EtOAC	22
3	MeCN	trace
4	acetone	trace
5	THF	trace
6	toulene	trace
7	DMF	trace
8	DMSO	trace
9	AcOH	50
10	MeOH	74
11	ethylene glycol	trace
12	glycerin	trace
13	EtOH	51
14	Me3COH	47
15	2-methoxyethanol	25
16	Me2CHOH	61
17	trifluorethanol	63
18c	MeOH	38
19d	MeOH	60
20e	MeOH	73

^a Reaction conditions: in the first step: amine (0.5 mmol), MeOH (1.0 mL), HCl (3 M, 0.5 mL), H₂O (0.5 mL), NaNO₂ (0.035 g), 0–5 °C, 30 min; in the second step: B₂pin₂ (1.5 mmol), solvent (1.0 mL), r.t., 1 h.

^b Isolated yield;

^c Conditions: 1 equiv bis(pinacolato)diboron was used.

^d Conditions: 2 equiv bis(pinacolato)diboron were used.

^e Conditions: 4 equiv bis(pinacolato)diboron were used.

With the optimal conditions in hand, the substrate scope was subsequently investigated.[17] First, a wide range of aryl amines 1 with substitutes, such as alkyl, OMe, NO₂, COOEt, Br, CN, Cl, F, I, CN, NH₂, OCF₃, and OH in the phenyl, underwent coupling with B₂pin₂ (2) at ambient temperature, and the desired products were isolated in good yields. The results shown in Table [2] indicate that aryl amines with electron-withdrawing or electron-donating substituents all could give the desired products with good yields. The borylation showed good tolerance to various functional groups on the aryl amines such as OH, CO₂Et, CN, CX (X = F, Cl, Br, and I) under the reaction conditions, and excellent yields were achieved for the reactions (2d–m). Notably, the amine group could be transformed to the boronate group selectively simply by controlling the amount of hydrochloric acid and sodium nitrite. For the substrate p-phenylenediamine, the desired monoamine and monoproduct 2l could be obtained with 53% yield without protection of the amino group. At the same time, for the substrate 4,4′-diaminobiphenyl, the desired diboronate product 2x is obtained with 75% yield by doubling the amount of hydrochloric acid and sodium nitrite. Disubstituted aromatic amines were also tested, giving good yields (Table [2, 2u,v]). The substrate scope could also be extended to amines with a naphthyl ring or biphenyl (Table [2, 2w–x]). All these arylboronates have found widespread applications in organic synthesis, as represented by the Suzuki–Miyaura cross-coupling reaction. In addition, bis(neopentyl glycolato)diboron can play the same role that react with arylamine at the same reaction conditions. As shown in Scheme [2], the desired borylated product 4a could be obtained with 65% isolated yield (Scheme [2]), which suggested its potential application for the preparation of arylboronates.

In the next step, we apply our process toward the synthesis of arylboronic acids with tetrahydroxydiboron [B₂(OH)₄] as boron source.[14] A wide range of aryl amines 1 with substitutes, such as alkyl, OMe, F, Cl, Br, NO₂, and COOEt in the phenyl, underwent coupling with B₂(OH)₄ at ambient temperature, and the desired products were isolated in good yields. The results shown in Table 3[19] indicate that aryl amines with electron-withdrawing or electron-donating substituents all could give the desired products with good yields. Likewise, this borylation showed good tolerance to various functional groups on the aryl amines such as CO₂Et, NO₂, CX (X = F, Cl, Br) under the reaction conditions, and excellent yields were achieved for the reactions (3d–f,h,i), which are available for further functionalization.

To test the viability of the method with more complex substrates, we applied the borylation to the preparation of heterocyclic boronate 2z, which is usually not easy to synthesize and use as the key intermediate for the synthesis of 3z,[18] a potent inhibitor for the treatment of osteoporosis (Scheme [3]).

Table 2 The Synthesis of Arylboronates from Arylamines with Bis(pinacolato)borane as Boron Source

Entry	Substrate	Product	Yield (%)b
1	1a	2a	74
2	1b	2b	57
3	1c	2c	86
4	1d	2d	54
5	1e	2e	62
6	1f	2f	73
7	1g	2g	77
8	1h	2h	55
9	1i	2i	75
10	1j	2j	57
11	1k	2k	97
12	1l	2l	53
13	1m	2m	93
14	1n	2n	45
15	1o	2o	48
16	1p	2p	60
17	1q	2q	62
18	1r	2r	52
19	1s	2s	55
20	1t	2t	96
21	1u	2u	72
22	1v	v	96
23	1w	2w	85
24	1x	2x	75

^a Reaction conditions: in the first step: amine (0.5 mmol), MeOH (1.0 mL), HCl (3 M, 0.5 mL), H₂O (0.5 mL), NaNO₂ (0.035 g), 0–5 °C, 30 min; in the second step: B₂pin₂ (1.5 mmol), MeOH (1.0 mL), r.t., 1 h.

^b Isolated yield.

^c Conditions: HCl (1.0 mL), H₂O (1.0 mL).

In addition, the borylation of p-anisidine at a 2 g scale was carried out under the conditions of Scheme [4], giving the desired 4-methoxyphenylboronic ester in 83% isolated yield, which demonstrate the practical applicability of the method (Scheme [4]).

To gain understanding of the reaction mechanism, the following borylation reaction of 4-toluidine with bis(pinacolato)diboron as boron source in methanol was carried out. In the presence of radical trap, 2,2,6,6-tetramethylpiperidinoxyl (TEMPO), the desired compound was obtained with 74% isolated yield (Scheme [5], eq. 1). However, unlike the results reported by Wang,[13] the addition of ­TEMPO to the borylation reaction of 4-toluidine with bis(pinacolato)diboron did not suppressed the borylation process significantly, the same borylated product was isolated with 68% yield (Scheme [5], eq. 2), which lends support that the radical species were not involved in our borylation reaction and a direct nucleophilic borylation via a SN₂Ar pathway maybe preferred.

Table 3 The Synthesis of Arylboronic Acids from Arylamines with Tetrahydroxydiboron B₂(OH)₄ as Boron Source^a

Entry	Substrate	Product	Yield (%)b
1	1b	3b	72
2	1a	3a	90
3	1c	3c	86
4	1d	3d	67
5	1e	3e	73
6	1f	3f	74
7	1y	3g	62
8	1k	3h	55
9	1i	3i	65
10	1u	3j	73
11	1v	3k	65

^a Reaction conditions: in the first step: amine (0.5 mmol), MeOH (1.0 mL), HCl (3 M, 0.5 mL), H₂O (0.5 mL), NaNO₂ (0.035 g), 0–5 °C, 30 min; in the second step: B₂(OH)₄ (1.5 mmol), MeOH (1.0 mL), r.t., 1 h.

^b Isolated yield.

A plausible mechanism is shown in Scheme [6] on the basis of the above experiments. First, a nucleophilic boryl moiety was formed by activation of the diboron reagent under the effect of methanol, this preactivation increases the reactivity of the diboron compounds. The aryldiazonium cation generated from aryl amine is the electrophile (Scheme [5], eq. 3) and the activated diboron reagent is a nucleophile. Then, the activated boron intermediate A attacks the aryl diazonium salt to form transient intermediate B via a SN₂Ar pathway, which is subsequently transformed into the borylation product through N₂ elimination and 2-methoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane C formation. The latter compound is confirmed by ¹¹B NMR spectroscopic study.

In conclusion, an effective methanol-promoted coupling of arylamine with diboron compounds at room temperature has been developed under metal-free conditions. This protocol could be applied to the synthesis of arylboronic acids utilizing arylamine and tetrahydroxydiboron B₂(OH)₄, bis(pinacolato)diboron and bis(neopentyl glycolato)diboron as boron source. This borylation process has the following features: (1) arylamines are inexpensive and easily available starting materials; (2) the borylation showed good tolerance to various functional groups on the aryl amines; (3) sodium nitrite is used as diazotization agent; (4) the reaction is carried out at room temperature without the use of catalyst, which provide a simple and green synthetic method to arylboronic acids and arylboronates.

Acknowledgment

We are grateful for the financial support of the National Natural Science Foundation of China (21372148) and by the 111 Project, Program for Chang Jiang Scholars and Innovative Research Team in University (IRT 1070), and Shaanxi Innovative Team of Key Science and Technology (2013KCT-17).

• References and Notes


For reviews of applications of arylboronates and arylboronic acid derivatives, see:
• 1a Miyaura N In Metal-Catalyzed Cross-Coupling Reactions. Meijere AD. Wiley-VCH; Weinheim: 2004. 2nd ed., 125
  Search in Google Scholar
• 1b Suzuki A In Boronic Acids: Preparation and Applications in Organic Synthesis and Medicine. Hall DG. Wiley-VCH; Weinheim: 2005: 123
  Search in Google Scholar
• 1c Suzuki A In Metal-Catalyzed Cross-Coupling Reactions. Diederich F, Stang PJ. Wiley-VCH; Weinheim: 1998: 49
  Search in Google Scholar
• 2a Suzuki A. Acc. Chem. Res. 1982; 15: 178
  CrossrefSearch in Google Scholar
• 2b Miyaura N, Suzuki A. Chem. Rev. 1995; 95: 2457
  Search in Google Scholar
• 2c Miyaura N. Top. Curr. Chem. 2002; 219: 11
  Search in Google Scholar
• 2d Kotha S, Lahiri K, Kashinath D. Tetrahedron 2002; 58: 9633
  CrossrefSearch in Google Scholar
• 2e Miyaura N. J. Organomet. Chem. 2002; 653: 54
  Search in Google Scholar
• 2f Miyaura N. Bull. Chem. Soc. Jpn. 2008; 81: 1535
  CrossrefSearch in Google Scholar
• 3a Brown HC, Srebnik M, Cole TE. Organometallics 1986; 5: 2300
  CrossrefSearch in Google Scholar
• 3b Brown HC, Cole TE. Organometallics 1983; 2: 1316
  CrossrefSearch in Google Scholar
• 3c Pintaric C, Olivero S, Gimbert Y, Chavant PY, Duñach E. J. Am. Chem. Soc. 2010; 132: 11825
  CrossrefSearch in Google Scholar
• 4a Ishiyama T, Murata M, Miyaura N. J. Org. Chem. 1995; 60: 7508
  CrossrefSearch in Google Scholar
• 4b Ishiyama T, Miyaura N. J. Organomet. Chem. 2000; 611: 392
  CrossrefSearch in Google Scholar
• 4c Murata M, Watanabe S, Masuda Y. J. Org. Chem. 1997; 62: 6458
  CrossrefSearch in Google Scholar
• 4d Murata M, Oyama T, Watanbe S, Masuda Y. J. Org. Chem. 2000; 65: 164
  CrossrefSearch in Google Scholar
• 4e Baudoin O, Guénard D, Guéritte F. J. Org. Chem. 2000; 65: 9268
  CrossrefPubMedSearch in Google Scholar
• 4f Broutin P, Cerna I, Campaniello M, Leroux F, Colobert F. Org. Lett. 2004; 6: 4419
  CrossrefSearch in Google Scholar
• 4g Murata M, Sambommatsu T, Watanabe S, Masuda Y. Synlett 2006; 1867
  Thieme Connect

For reviews, see:
• 5a Ishiyama T, Miyaura N. J. Organomet. Chem. 2003; 680: 3
  CrossrefSearch in Google Scholar
• 5b Mkhalid IA. I, Barnard JH, Marder TB, Murphy JC, Hartwig JF. Chem. Rev. 2010; 110: 890
  CrossrefPubMedSearch in Google Scholar
• 5c Ishiyama T, Miyaura N. Chem. Rec. 2004; 3: 271
  CrossrefSearch in Google Scholar
• 5d Hartwig JF. Chem. Soc. Rev. 2011; 40: 1992
  CrossrefPubMedSearch in Google Scholar

For recent examples of transition-metal-catalyzed boryl substitution of haloarenes and arene C–H borylation, see:
• 6a Dai H.-X, Yu J.-Q. J. Am. Chem. Soc. 2012; 134: 134
  CrossrefSearch in Google Scholar
• 6b Sogabe Y, Namikoshi T, Watanabe S, Murata M. Synthesis 2012; 44: 1233
  Thieme ConnectSearch in Google Scholar
• 6c Kawamorita S, Ohmiya H, Iwai T, Sawamura M. Angew. Chem. Int. Ed. 2011; 50: 8363
  CrossrefSearch in Google Scholar
• 6d Kawamorita S, Miyazaki T, Ohmiya H, Iwai T, Sawamura M. J. Am. Chem. Soc. 2011; 133: 19310
  CrossrefSearch in Google Scholar
• 6e Yamamoto T, Morita T, Takagi J, Yamakawa T. Org. Lett. 2011; 13: 5766
  CrossrefSearch in Google Scholar
• 6f Tang W, Keshipeddy S, Zhang Y, Wei X, Savoie J, Patel ND, Yee NK, Senanayake CH. Org. Lett. 2011; 13: 1366
  CrossrefSearch in Google Scholar
• 6g Ros A, Estepa B, López-Rodríguez R, Álvarez E, Fernández R, Lassaletta JM. Angew. Chem. Int. Ed. 2011; 50: 11724
  CrossrefPubMedSearch in Google Scholar
• 6h Nguyen DH, Pérez-Torrente JJ, Lomba L, Victoria Jiménez M, Lahoz FJ, Oro LA. Dalton Trans. 2011; 40: 8429
  CrossrefSearch in Google Scholar
• 6i Kleeberg C, Dang L, Lin ZY, Marder TB. Angew. Chem. Int. Ed. 2009; 48: 5350
  CrossrefSearch in Google Scholar

For reviews, see:
• 7a Ingleson MJ. Synlett 2012; 23: 1411
  Thieme ConnectSearch in Google Scholar
• 7b De Vries TS, Prokofjevs A, Vedejs E. Chem. Rev. 2012; 112: 4246
  CrossrefPubMedSearch in Google Scholar

For recent examples, see:
• 7c Ishida N, Moriya T, Goya T, Murakami M. J. Org. Chem. 2010; 75: 8709
  Search in Google Scholar
• 7d Del Grosso A, Muryn CA, Pritchard RG, Ingleson M. J. Organometallics 2010; 29: 241
  CrossrefSearch in Google Scholar
• 7e Del Grosso A, Singleton PJ, Muryn CA, Ingleson MJ. Angew. Chem. Int. Ed. 2011; 50: 2102
  CrossrefSearch in Google Scholar
• 7f Hatakeyama T, Hashimoto S, Seki S, Nakamura M. J. Am. Chem. Soc. 2011; 133: 18614
  CrossrefPubMedSearch in Google Scholar
• 7g Prokofjevs A, Kampf JW, Vedejs E. Angew. Chem. Int. Ed. 2011; 50: 2098
  CrossrefSearch in Google Scholar
• 7h Del GrossoA, Helm MD, Solomon SA, Caras-Quintero D, Ingleson MJ. Chem. Commun. 2011; 47: 12459
  CrossrefSearch in Google Scholar
• 7i Solomon SA, Del Grosso A, Clark ER, Bagutski V, McDouall JJ. W, Ingleson M. J. Organometallics 2012; 31: 1908
  CrossrefSearch in Google Scholar
• 7j Niu L, Yang H, Yang D, Fua H. Adv. Synth. Catal. 2012; 354: 2211
  CrossrefSearch in Google Scholar
• 7k Niu L, Yang H, Wang R, Fu H. Org. Lett. 2012; 14: 2618
  CrossrefSearch in Google Scholar
• 8 Yamamoto E, Izumi K, Horita Y, Ito H. J. Am. Chem. Soc. 2012; 134: 19997
  CrossrefSearch in Google Scholar
• 9 Mo F, Dong G, Zhang Y, Wang J. Org. Biomol. Chem. 2013; 11: 1582
  CrossrefPubMedSearch in Google Scholar
• 10a Chemistry of the Diazonium and Diazo Groups. Patai S. Wiley-Blackwell; New York: 1978. Part 1
  CrossrefSearch in Google Scholar
• 10b Chemistry of the Diazonium and Diazo Groups. Patai S. Wiley-Blackwell; New York: 1978. Part 2
  Search in Google Scholar
• 11a Ma YD, Song C, Jiang W, Xue GP, CannonJ F, Wang XM, Andrus MB. Org. Lett. 2003; 5: 4635
  Search in Google Scholar
• 11b Willis DM, Strongin RM. Tetrahedron Lett. 2000; 8: 683
  Search in Google Scholar
• 11c Zhang J, Wang XL, Yu HT, Ye JH. Synlett 2012; 23: 1394
  Thieme ConnectSearch in Google Scholar
• 12 Yu J, Zhang L, Yan GB. Adv. Synth. Catal. 2012; 354: 2625
  CrossrefSearch in Google Scholar
• 13a Mo F, Jiang Y, Qiu D, Zhang Y, Wang J. Angew. Chem. Int. Ed. 2010; 49: 1846
  CrossrefSearch in Google Scholar
• 13b Qiu D, Jin L, Zheng Z, Meng H, Mo F, Wang X, Zhang Y, Wang J. J. Org. Chem. 2013; 78: 1923
  CrossrefSearch in Google Scholar

For borylation utilizing bisboronic acid, see:
• 14a Molander GA, Trice SL. J. S, Kennedy M, Dreher SD, Tudge MT. J. Am. Chem. Soc. 2012; 134: 11667
  CrossrefSearch in Google Scholar
• 14b Molander GA, Trice SL. J, Dreher SD. J. Am. Chem. Soc. 2010; 132: 17701
  CrossrefSearch in Google Scholar
• 14c Molander GA, Cavalcanti LN, García-García C. J. Org. Chem. 2013; 78: 6427
  CrossrefSearch in Google Scholar
• 15 Xue D, Jia Z.-H, Zhao C.-J, Zhang Y.-Y, Wang C, Xiao J.-L. Chem. Eur. J. 2014; 20: 2960
  CrossrefSearch in Google Scholar
• 16 Hoffman RV. Org. Synth. 1981; 60: 121
  CrossrefSearch in Google Scholar
• 17 General Procedure for the Synthesis of Aryboronate Esters To a solution of arylamine (0.5 mmol, 1.0 equiv) in MeOH (1.0 mL) was added HCl (0.5 mL, 1.5 mmol, 3.0 equiv) followed by H₂O (0.5 ml). This mixture was stirred 2 min, and the NaNO₂ solution (0.25 mL) was then added. The NaNO₂ solution was prepared by dissolving 35 mg of NaNO₂ in H₂O (0.25 mL). This mixture was stirred 30 min at 0–5 °C followed by B₂pin₂ (2, 381 mg, 1.5 mmol, 3.0 equiv) in MeOH (1.0 mL). This mixture was stirred 60 min. H₂O (10 mL) was added to the reaction mixture, then extracted with CH₂Cl₂ (50 mL, 3×). The combined organic layers were washed with sat. NaHCO₃, dried over Na₂SO₄, followed by evaporation, and the crude residue was purified by flash chromatography.
• 18 Chen C.-Y, Dagneau P, Grabowski EJ. J, Oballa R, O’Shea P, Prasit P, Robichaud J, Tillyer R, Wang X. J. Org. Chem. 2003; 68: 2633
  CrossrefSearch in Google Scholar
• 19 General Procedure for the Synthesis of Arylboronic Acids To a solution of arylamine (0.5 mmol, 1.0 equiv) in MeOH (1.0 mL) was added HCl (0.5 mL, 1.5 mmol, 3.0 equiv), followed by H₂O (0.5 ml). This mixture was stirred 2 min, and the NaNO₂ solution (0.25 mL) was then added. The NaNO₂ solution was prepared by dissolving 35 mg of NaNO₂ in H₂O (0.25 mL). This mixture was stirred 30 min at 0–5 °C, followed by HCl (135 mg, 1.5 mmol, 3.0 equivalents) in MeOH (1.0 mL). This mixture was stirred 60 min. H₂O (10 mL) was added to reaction mixture, then extracted with CH₂Cl₂ (50 mL, 3×). The combined organic layer was dried over Na₂SO₄, followed by evaporation to give the products.

• References and Notes


For reviews of applications of arylboronates and arylboronic acid derivatives, see:
• 1a Miyaura N In Metal-Catalyzed Cross-Coupling Reactions. Meijere AD. Wiley-VCH; Weinheim: 2004. 2nd ed., 125
  Search in Google Scholar
• 1b Suzuki A In Boronic Acids: Preparation and Applications in Organic Synthesis and Medicine. Hall DG. Wiley-VCH; Weinheim: 2005: 123
  Search in Google Scholar
• 1c Suzuki A In Metal-Catalyzed Cross-Coupling Reactions. Diederich F, Stang PJ. Wiley-VCH; Weinheim: 1998: 49
  Search in Google Scholar
• 2a Suzuki A. Acc. Chem. Res. 1982; 15: 178
  CrossrefSearch in Google Scholar
• 2b Miyaura N, Suzuki A. Chem. Rev. 1995; 95: 2457
  Search in Google Scholar
• 2c Miyaura N. Top. Curr. Chem. 2002; 219: 11
  Search in Google Scholar
• 2d Kotha S, Lahiri K, Kashinath D. Tetrahedron 2002; 58: 9633
  CrossrefSearch in Google Scholar
• 2e Miyaura N. J. Organomet. Chem. 2002; 653: 54
  Search in Google Scholar
• 2f Miyaura N. Bull. Chem. Soc. Jpn. 2008; 81: 1535
  CrossrefSearch in Google Scholar
• 3a Brown HC, Srebnik M, Cole TE. Organometallics 1986; 5: 2300
  CrossrefSearch in Google Scholar
• 3b Brown HC, Cole TE. Organometallics 1983; 2: 1316
  CrossrefSearch in Google Scholar
• 3c Pintaric C, Olivero S, Gimbert Y, Chavant PY, Duñach E. J. Am. Chem. Soc. 2010; 132: 11825
  CrossrefSearch in Google Scholar
• 4a Ishiyama T, Murata M, Miyaura N. J. Org. Chem. 1995; 60: 7508
  CrossrefSearch in Google Scholar
• 4b Ishiyama T, Miyaura N. J. Organomet. Chem. 2000; 611: 392
  CrossrefSearch in Google Scholar
• 4c Murata M, Watanabe S, Masuda Y. J. Org. Chem. 1997; 62: 6458
  CrossrefSearch in Google Scholar
• 4d Murata M, Oyama T, Watanbe S, Masuda Y. J. Org. Chem. 2000; 65: 164
  CrossrefSearch in Google Scholar
• 4e Baudoin O, Guénard D, Guéritte F. J. Org. Chem. 2000; 65: 9268
  CrossrefPubMedSearch in Google Scholar
• 4f Broutin P, Cerna I, Campaniello M, Leroux F, Colobert F. Org. Lett. 2004; 6: 4419
  CrossrefSearch in Google Scholar
• 4g Murata M, Sambommatsu T, Watanabe S, Masuda Y. Synlett 2006; 1867
  Thieme Connect

For reviews, see:
• 5a Ishiyama T, Miyaura N. J. Organomet. Chem. 2003; 680: 3
  CrossrefSearch in Google Scholar
• 5b Mkhalid IA. I, Barnard JH, Marder TB, Murphy JC, Hartwig JF. Chem. Rev. 2010; 110: 890
  CrossrefPubMedSearch in Google Scholar
• 5c Ishiyama T, Miyaura N. Chem. Rec. 2004; 3: 271
  CrossrefSearch in Google Scholar
• 5d Hartwig JF. Chem. Soc. Rev. 2011; 40: 1992
  CrossrefPubMedSearch in Google Scholar

For recent examples of transition-metal-catalyzed boryl substitution of haloarenes and arene C–H borylation, see:
• 6a Dai H.-X, Yu J.-Q. J. Am. Chem. Soc. 2012; 134: 134
  CrossrefSearch in Google Scholar
• 6b Sogabe Y, Namikoshi T, Watanabe S, Murata M. Synthesis 2012; 44: 1233
  Thieme ConnectSearch in Google Scholar
• 6c Kawamorita S, Ohmiya H, Iwai T, Sawamura M. Angew. Chem. Int. Ed. 2011; 50: 8363
  CrossrefSearch in Google Scholar
• 6d Kawamorita S, Miyazaki T, Ohmiya H, Iwai T, Sawamura M. J. Am. Chem. Soc. 2011; 133: 19310
  CrossrefSearch in Google Scholar
• 6e Yamamoto T, Morita T, Takagi J, Yamakawa T. Org. Lett. 2011; 13: 5766
  CrossrefSearch in Google Scholar
• 6f Tang W, Keshipeddy S, Zhang Y, Wei X, Savoie J, Patel ND, Yee NK, Senanayake CH. Org. Lett. 2011; 13: 1366
  CrossrefSearch in Google Scholar
• 6g Ros A, Estepa B, López-Rodríguez R, Álvarez E, Fernández R, Lassaletta JM. Angew. Chem. Int. Ed. 2011; 50: 11724
  CrossrefPubMedSearch in Google Scholar
• 6h Nguyen DH, Pérez-Torrente JJ, Lomba L, Victoria Jiménez M, Lahoz FJ, Oro LA. Dalton Trans. 2011; 40: 8429
  CrossrefSearch in Google Scholar
• 6i Kleeberg C, Dang L, Lin ZY, Marder TB. Angew. Chem. Int. Ed. 2009; 48: 5350
  CrossrefSearch in Google Scholar

For reviews, see:
• 7a Ingleson MJ. Synlett 2012; 23: 1411
  Thieme ConnectSearch in Google Scholar
• 7b De Vries TS, Prokofjevs A, Vedejs E. Chem. Rev. 2012; 112: 4246
  CrossrefPubMedSearch in Google Scholar

For recent examples, see:
• 7c Ishida N, Moriya T, Goya T, Murakami M. J. Org. Chem. 2010; 75: 8709
  Search in Google Scholar
• 7d Del Grosso A, Muryn CA, Pritchard RG, Ingleson M. J. Organometallics 2010; 29: 241
  CrossrefSearch in Google Scholar
• 7e Del Grosso A, Singleton PJ, Muryn CA, Ingleson MJ. Angew. Chem. Int. Ed. 2011; 50: 2102
  CrossrefSearch in Google Scholar
• 7f Hatakeyama T, Hashimoto S, Seki S, Nakamura M. J. Am. Chem. Soc. 2011; 133: 18614
  CrossrefPubMedSearch in Google Scholar
• 7g Prokofjevs A, Kampf JW, Vedejs E. Angew. Chem. Int. Ed. 2011; 50: 2098
  CrossrefSearch in Google Scholar
• 7h Del GrossoA, Helm MD, Solomon SA, Caras-Quintero D, Ingleson MJ. Chem. Commun. 2011; 47: 12459
  CrossrefSearch in Google Scholar
• 7i Solomon SA, Del Grosso A, Clark ER, Bagutski V, McDouall JJ. W, Ingleson M. J. Organometallics 2012; 31: 1908
  CrossrefSearch in Google Scholar
• 7j Niu L, Yang H, Yang D, Fua H. Adv. Synth. Catal. 2012; 354: 2211
  CrossrefSearch in Google Scholar
• 7k Niu L, Yang H, Wang R, Fu H. Org. Lett. 2012; 14: 2618
  CrossrefSearch in Google Scholar
• 8 Yamamoto E, Izumi K, Horita Y, Ito H. J. Am. Chem. Soc. 2012; 134: 19997
  CrossrefSearch in Google Scholar
• 9 Mo F, Dong G, Zhang Y, Wang J. Org. Biomol. Chem. 2013; 11: 1582
  CrossrefPubMedSearch in Google Scholar
• 10a Chemistry of the Diazonium and Diazo Groups. Patai S. Wiley-Blackwell; New York: 1978. Part 1
  CrossrefSearch in Google Scholar
• 10b Chemistry of the Diazonium and Diazo Groups. Patai S. Wiley-Blackwell; New York: 1978. Part 2
  Search in Google Scholar
• 11a Ma YD, Song C, Jiang W, Xue GP, CannonJ F, Wang XM, Andrus MB. Org. Lett. 2003; 5: 4635
  Search in Google Scholar
• 11b Willis DM, Strongin RM. Tetrahedron Lett. 2000; 8: 683
  Search in Google Scholar
• 11c Zhang J, Wang XL, Yu HT, Ye JH. Synlett 2012; 23: 1394
  Thieme ConnectSearch in Google Scholar
• 12 Yu J, Zhang L, Yan GB. Adv. Synth. Catal. 2012; 354: 2625
  CrossrefSearch in Google Scholar
• 13a Mo F, Jiang Y, Qiu D, Zhang Y, Wang J. Angew. Chem. Int. Ed. 2010; 49: 1846
  CrossrefSearch in Google Scholar
• 13b Qiu D, Jin L, Zheng Z, Meng H, Mo F, Wang X, Zhang Y, Wang J. J. Org. Chem. 2013; 78: 1923
  CrossrefSearch in Google Scholar

For borylation utilizing bisboronic acid, see:
• 14a Molander GA, Trice SL. J. S, Kennedy M, Dreher SD, Tudge MT. J. Am. Chem. Soc. 2012; 134: 11667
  CrossrefSearch in Google Scholar
• 14b Molander GA, Trice SL. J, Dreher SD. J. Am. Chem. Soc. 2010; 132: 17701
  CrossrefSearch in Google Scholar
• 14c Molander GA, Cavalcanti LN, García-García C. J. Org. Chem. 2013; 78: 6427
  CrossrefSearch in Google Scholar
• 15 Xue D, Jia Z.-H, Zhao C.-J, Zhang Y.-Y, Wang C, Xiao J.-L. Chem. Eur. J. 2014; 20: 2960
  CrossrefSearch in Google Scholar
• 16 Hoffman RV. Org. Synth. 1981; 60: 121
  CrossrefSearch in Google Scholar
• 17 General Procedure for the Synthesis of Aryboronate Esters To a solution of arylamine (0.5 mmol, 1.0 equiv) in MeOH (1.0 mL) was added HCl (0.5 mL, 1.5 mmol, 3.0 equiv) followed by H₂O (0.5 ml). This mixture was stirred 2 min, and the NaNO₂ solution (0.25 mL) was then added. The NaNO₂ solution was prepared by dissolving 35 mg of NaNO₂ in H₂O (0.25 mL). This mixture was stirred 30 min at 0–5 °C followed by B₂pin₂ (2, 381 mg, 1.5 mmol, 3.0 equiv) in MeOH (1.0 mL). This mixture was stirred 60 min. H₂O (10 mL) was added to the reaction mixture, then extracted with CH₂Cl₂ (50 mL, 3×). The combined organic layers were washed with sat. NaHCO₃, dried over Na₂SO₄, followed by evaporation, and the crude residue was purified by flash chromatography.
• 18 Chen C.-Y, Dagneau P, Grabowski EJ. J, Oballa R, O’Shea P, Prasit P, Robichaud J, Tillyer R, Wang X. J. Org. Chem. 2003; 68: 2633
  CrossrefSearch in Google Scholar
• 19 General Procedure for the Synthesis of Arylboronic Acids To a solution of arylamine (0.5 mmol, 1.0 equiv) in MeOH (1.0 mL) was added HCl (0.5 mL, 1.5 mmol, 3.0 equiv), followed by H₂O (0.5 ml). This mixture was stirred 2 min, and the NaNO₂ solution (0.25 mL) was then added. The NaNO₂ solution was prepared by dissolving 35 mg of NaNO₂ in H₂O (0.25 mL). This mixture was stirred 30 min at 0–5 °C, followed by HCl (135 mg, 1.5 mmol, 3.0 equivalents) in MeOH (1.0 mL). This mixture was stirred 60 min. H₂O (10 mL) was added to reaction mixture, then extracted with CH₂Cl₂ (50 mL, 3×). The combined organic layer was dried over Na₂SO₄, followed by evaporation to give the products.

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