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DOI: 10.1055/a-2153-6594
Desulfonylative Radical Truce–Smiles Rearrangement Utilizing the Benzimidazoline and Benzimidazolium Redox Couple
This study was supported by the Japan Society for the Promotion of Science (JSPS KAKENHI, Grant JP 19K05435 for E.H.).
This letter is dedicated to Professor Dennis P. Curran (University of Pittsburgh), who is a distinguished chemist for synthetic application of free radical chemistry, on the occasion of his Koki anniversary (70th birthday).
Abstract
We have developed protocols for promoting redox reactions utilizing the 2-substituted 1,3-dimethylbenzimidazoline (BIH–R) and benzimidazolium (BI+–R) couples which were applied to the desulfonylative radical Truce–Smiles rearrangement. Expected rearrangement products formed in modest to good yields in these processes, in which added or in situ generated BIH–R serve as electron- and hydrogen-atom-donating reagents or photocatalysts. DFT calculations were carried out to gain the information about the radical intermediates involved in the rearrangement reaction.
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Key words
benzimidazoline and benzimidazolium redox couple - single-electron transfer - photoreducing catalyst - radical Truce–Smiles rearrangement - desulfonylative aryl migrationReduction and oxidation (redox) reactions in chemical and biological systems frequently proceed through mechanistic pathways involving single-electron transfer (SET) between electron donors and acceptors.[1] SET from or to neutral organic substances to or from appropriate redox reagents or catalysts produces radical ions which often undergo bond cleavage to form radical and ionic intermediates.[2] Benzimidazolines (dihydrobenzimidazoles, BIH–R), which are analogues of the reduced form of nicotinamide adenine dinucleotide (NADH), serve as effective electron and hydrogen (hydride, hydrogen atom, and proton) donors (Scheme [1]).[3] Applications of BIH–R in a variety of chemical processes have been reported.[4] In contrast, the redox reactivity of the corresponding oxidized forms, benzimidazoliums (BI+–R) has been explored to a lesser extent.[5] Our past studies of thermal as well as photochemical reactions involving BIH–R and BI+–R redox couples[4d] [k] led to the development of a new series of BIH–R photoreductants[6] and BI+–R photocatalysts.[7] [8] [9]
The classical Truce–Smiles rearrangement is an intramolecular nucleophilic aromatic substitution reaction involving aryl migration of anionic intermediates.[10] Recently, the radical version of this process promoted by photoinduced electron transfer (PET) has received attention.[11] Several years ago, Zhang et al. reported that α-bromo-N-aryl-N-arylsulfonyl amides undergo desulfonylative aryl migration reactions, recognized as Truce–Smiles rearrangement, promoted by an iridium photocatalyst.[12] These findings stimulated our interest in applying the protocol utilizing the BIH–R and BI+–R redox couple to promote this radical Truce–Smiles rearrangement. In a preliminary effort aimed at this goal, we found that 2-bromo-2-methyl-N-phenyl-N-phenylsulfonylpropaneamide undergoes the rearrangement to form 2-methyl-2-phenyl-N-phenyl-propaneamide when our originally developed organophotocatalysts, such as triarylamine-substituted benzimidazoliums (BI+–PhNAr2), along with N,N-diisopropylethylamine (DIPEA) and acetic acid are used (above in Scheme [2]).[8] In a recent investigation, we also developed processes in which BIH–R are employed to induce debrominative oxygenation reactions of α-bromoketones and -esters under an air atmosphere, at room temperature, and without light irradiation.[13] This observation suggests that the newly developed redox-based activation protocol would also be applicable to Truce–Smiles rearrangement reaction of 2-bromo-N-phenylsulfonylpropaneamides. A study guided by this proposal demonstrated that, as expected, BIH–R 1-H reductants and photocatalytic system of BI+–R 1 cooperating with appropriate additives to promote radical Truce–Smiles rearrangements of 2-bromo-2-methyl-N-aryl-N-arylsulfonylpropaneamides (2, below in Scheme [2]). The results of this effort are described and discussed below.
In the first stage of this study, we explored desulfonylative Truce–Smiles rearrangement reactions of amides 2a–e photocatalyzed by 1f using the conditions recently developed.[8] Unfortunately, except for the reaction of 2a that generates 3a in good yield (67%), the processes proceed in unexpectedly low yields of other 3 (23–35%, Scheme [3], see details in Table S1 in the Supporting Information).
These observations prompted us to develop alternative protocols to promote these rearrangement reactions. As suggested by the results of a previous investigation,[13] we examined reactions of amide 2a using benzimidazolines 1-H in the absence of light irradiation, which showed that several factors influence the yield of 3a. As shown in Table [1] (also Table S2), employing the appropriate benzimidazolines 1a-H, 1b-H, and 1e-H is essential for optimization of the desulfonylative Truce–Smiles rearrangement reaction. In addition, the quantity of each benzimidazoline utilized influences the yield of 3a (see entries 1–4, compare entry 6 to 7 and entry 8 to 9). Moreover, both DMF and DMSO are suitable solvents (entries 4 and 5), and others including MeCN, CH2Cl2 THF, and PhMe are not (Table S2). Finally, the presence of proton donors such as H2O and AcOH leads to slight increases in the yield of 3a (entries 10 and 11), while addition of Et2NH appears to have the reverse effect. The combined results show that conditions in which 1e-H is the promoter, DMF is the solvent, and AcOH is an additive are optimal for carrying out the conversion of 2 into 3 (Scheme [4]).[14a]
a 2a (0.10 mmol), solvent (2.0 mL), stirred at r.t. for 1 h.
b Determined by 1H NMR spectroscopy.
Next, the application of a catalytic protocol for the promotion of the radical Truce–Smiles rearrangement was probed. We previously developed a new photocatalytic system for redox reactions in which catalytic quantities of benzimidazolines 1-H, generated in situ from benzimidazoliums 1 by using stoichiometric quantities of a hydride reagent, serve as electron and hydrogen atom donor (eh-donor) photocatalysts.[7b] [9] An assessment of this approach showed that utilizing picoline borane (pic-BH3) to catalytically generate 1e-H from 1e does not promote the rearrangement of 2a in the absence of light irradiation, but it successfully induces the process when the reaction mixture is irradiated using a white light-emitting diode (LED; Scheme [5]).
A screen of several different conditions demonstrated that 1f·ClO4 displays a better performance than 1e·ClO4 and that the use of a Xe lamp as the light source shortens the time required to complete the process. The results of a study surveying the substrate compatibility of these processes showed that eh-donor-photocatalyzed reactions of 2 utilizing 1f·ClO4 and pic-BH3 in the presence of AcOH generate 3 in modest to good yields (Scheme [6]).[14b]
Several radical mechanisms could be responsible for the desulfonylative Truce–Smiles rearrangement reactions described above.[11] [12] Density functional theory (DFT) calculations were performed on 2a, its radical anion 2a •–, derived radicals 4a–7a, and transition states for their interconversion to gain information about the intermediates that are possibly involved in the pathway (Figure [1], also see Figures S1–S4 and Tables S3–S5 in the Supporting Information).[15] The calculations show that the α-amide alkyl radical 4a exists in two conformations, designated as A and B in Figure S4, and that conformer A has a large distance between the alkyl radical center and the ipso carbon on the phenylsulfonyl group (4.38 Å). Because this distance is much smaller in conformer B (3.04 Å, Table S5), B is likely the precursor of cyclized radical 5a. It is also suggested that transformation of 4a to 5a via transition state (TS1) is rate-determining in the radical pathway for this rearrangement. Furthermore, it is noteworthy that the calculations indicate that sulfonyl radical 6a exists as an energy minimum structure in the mechanistic route although such a possibility has not been previously considered.[12] Finally, the calculations show that the overall process transforming 4a into 7a is highly exergonic.
Based on the results of related studies carried out by us[8] and others,[12] as well as those arising from the DFT calculations for 2a, a plausible mechanistic pathway for 2a is depicted in Scheme [7], which could be also applicable for the desulfonylative Truce–Smiles rearrangement reactions of other substrates 2. In a similar manner to α-bromo ketones previously studied by us,[13] initial SET from reductant 1-H or in situ generated photocatalysts 1-H to LUMO of 2a (Figure S2) causes dissociative electron transfer,[16] because the activation energy of fragmentation of 2a •– appears to be minimal (Figure S3). Radical cations of 1-H (1-H•+ ) are co-generated in these SET processes. In the fragmentation step of 2a •–, C–Br bond cleavage occurs selectively to form 4a and bromide ion rather than an amide enolate and bromine radical that is further supported by DFT calculations (Table S4). Intramolecular radical addition of 4a giving 5a and subsequent C–S bond cleavage leads to generation of the rearranged sulfonyl radical 6a. Finally, desulfonylation of 6a takes place to generate amidyl radical 7a in which hydrogen atom transfer (HAT) from either 1-H•+ and/or DMF undergoes to produce 3a and 1. As we previously discussed,[8] an alternative route for completion of the Truce–Smiles reaction involves SET reduction of 7a followed by proton transfer (PT) to the resulting amide anion 8a from a proton donor such as AcOH. The catalytic cycle is completed by pic-BH3-promoted conversion of 1 into 1-H.
In conclusion, we have shown that the protocol utilizing the benzimidazoline and benzimidazolium redox couple, we developed previously, can be applied to the radical Truce–Smiles rearrangement. Characteristically, in these processes the benzimidazoline serves as an electron- and hydrogen-atom-donor (eh-donor) reagent without light[13] and photocatalysts regenerated from the benzimidazolium by hydride reagent.[7b] [9] Moreover, DFT calculations were performed to analyze the structure and energy changes taking place in the proposed radical mechanism. Further efforts will be aimed at optimization of conditions to achieve higher yields of the rearranged products, as well as at applications of the developed protocols to a wide range of substrates. Clearly, the results coming from this unprecedented application of benzimidazoline and benzimidazolium redox couples to the desulfonylative Truce–Smiles rearrangement, as well as those arising from the theoretical investigation of this process provide valuable information that is useful not only in the area of organic synthesis but also for other fields such as photochemistry, electron transfer chemistry, and radical chemistry.
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Conflict of Interest
The authors declare no conflict of interest.
Supporting Information
- Supporting information for this article is available online at https://doi-org.accesdistant.sorbonne-universite.fr/10.1055/a-2153-6594.
Experimental procedures, additional results of reactions, DFT calculations of radical
rearrangement, and 1H NMR charts of selected photoreaction mixtures (PDF) are included.
- Supporting Information
-
References and Notes
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- 1b Photoinduced Electron Transfer, Parts A–D. Fox MA, Chanon M. Elsevier; Amsterdam: 1988
- 1c Advances in Electron Transfer Chemistry, Vol. 1–6. Mariano PS. JAI; Greenwich: 1991
- 1d Kavarnos GJ. Fundamental of Photoinduced Electron Transfer. VCH; New York: 1993
- 1e Connelly NG, Geiger WE. Chem. Rev. 1996; 96: 877
- 1f Electron Transfer in Chemistry, Vol. 1–5. Balzani V. Wiley-VCH; Weinheim: 2001
- 1g Organic Electrochemistry, 4th ed. Lund H, Hammerich O. Marcel Dekker; New York: 2001
- 1h Fukuzumi S. Electron Transfer: Mechanisms and Applications . Wiley-VCH; Weinheim: 2020
- 2a Schmittel M, Burghart A. Angew. Chem., Int. Ed. Engl. 1997; 36: 2550
- 2b Berger DJ, Tanko JM. The Chemistry of Double-Bonded Functional Groups . Patai S. Wiley; New York: 1997: 1281
- 2c Roth HD. Reactive Intermediate Chemistry . Moss RA, Platz MS, Jones MJr. Wiley; Hoboken: 2004: 205
- 2d Todres ZV. Ion-Radical Organic Chemistry Principles and Applications, 2nd ed. CRC Press; Boca Raton: 2009
- 2e Zhang N, Samanta SR, Rosen BM, Percec V. Chem. Rev. 2014; 114: 5848
- 2f Studer A, Curran DP. Nat. Chem. 2014; 6: 765
- 2g Lee KN, Ngai M.-Y. Chem. Commun. 2017; 53: 13093
- 2h Syroeshkin MA, Kuriakose F, Saverina EA, Timofeeva VA, Egorov MP, Alabugin IV. Angew. Chem. Int. Ed. 2019; 58: 5532
- 2i Peter A, Agasti S, Knowles O, Pye E, Procter DJ. Chem. Soc. Rev. 2021; 50: 5349
- 3 Zhu X.-Q, Zhang M.-T, Yu A, Wang C.-H, Cheng J.-P. J. Am. Chem. Soc. 2008; 130: 2501
- 4a Chikashita H, Itoh K. Bull. Chem. Soc. Jpn. 1986; 59: 1747
- 4b Ramos SM, Tarazi M, Wuest JD. J. Org. Chem. 1987; 52: 5437
- 4c Chen J, Tanner DD. J. Org. Chem. 1988; 53: 3897
- 4d Hasegawa E, Kato T, Kitazume T, Yanagi K, Hasegawa K, Horaguchi T. Tetrahedron Lett. 1996; 37: 7079
- 4e Lee I.-SH, Jeoung EH, Kreevoy MM. J. Am. Chem. Soc. 1997; 119: 2722
- 4f Schwarz DE, Cameron TM, Hay PJ, Scott BL, Tumas W, Thorn DL. Chem. Commun. 2005; 5919
- 4g Wei P, Oh JH, Dong G, Bao Z. J. Am. Chem. Soc. 2010; 132: 8852
- 4h Tamaki Y, Koike K, Morimoto T, Ishitani O. J. Catal. 2013; 304: 22
- 4i Horn M, Schappele LH, Lang-Wittkowski G, Mayr H, Ofial AR. Chem. Eur. J. 2013; 19: 249
- 4j Kim SS, Bae S, Jo WH. Chem. Commun. 2015; 51: 17413
- 4k Hasegawa E, Takizawa S. Aust. J. Chem. 2015; 68: 1640
- 4l Zhang Y, Petersen JL, Milsmann CA. J. Am. Chem. Soc. 2016; 138: 13115
- 4m Mehrotra S, Raje S, Jain AK, Angamuthu R. ACS Sustainable Chem. Eng. 2017; 5: 6322
- 4n Iakovenko R, Hlaváč J. Green Chem. 2021; 23: 440
- 4o Tun SL, Mariappan SV. S, Pigge FC. J. Org. Chem. 2022; 87: 8059
- 4p Wang Y.-F, Zhang M.-T. J. Am. Chem. Soc. 2022; 144: 12459
- 5a Ilic S, Alherz A, Musgrave CB, Glusac KD. Chem. Commun. 2019; 55: 5583
- 5b Rohrbach S, Shah RS, Tuttle T, Murphy JA. Angew. Chem. Int. Ed. 2019; 58: 11454
- 5c Kodama T, Kubo M, Shinji W, Ohkubo K, Tobisu M. Chem. Sci. 2020; 11: 12109
- 5d Weerasooriya RB, Drummer MC, Phelan BT, Gesiorski JL, Sprague-Klein EA, Chen LX, Glusac KD. J. Phys. Chem. C 2022; 126: 17816
- 5e Xie W, Xu J, Md Idros U, Katsuhira J, Fuki M, Hayashi M, Yamanaka M, Kobori Y, Matsubara R. Nat. Chem. 2023; 15: 794
- 6a Hasegawa E, Ohta T, Tsuji S, Mori K, Uchida K, Miura T, Ikoma T, Tayama E, Iwamoto H, Takizawa S, Murata S. Tetrahedron 2015; 71: 5494
- 6b Hasegawa E, Nagakura Y, Izumiya N, Matsumoto K, Tanaka T, Miura T, Ikoma T, Iwamoto H, Wakamatsu K. J. Org. Chem. 2018; 83: 10813
- 6c Hasegawa E, Nakamura S, Oomori K, Tanaka T, Iwamoto H, Wakamatsu K. J. Org. Chem. 2021; 86: 2556
- 7a Hasegawa E, Izumiya N, Miura T, Ikoma T, Iwamoto H, Takizawa S, Murata S. J. Org. Chem. 2018; 83: 3921
- 7b Hasegawa E, Tanaka T, Izumiya N, Kiuchi T, Ooe Y, Iwamoto H, Takizawa S, Murata S. J. Org. Chem. 2020; 85: 4344
- 7c Tanaka T, Kiuchi T, Ooe Y, Iwamoto H, Takizawa S, Murata S, Hasegawa E. ACS Omega 2022; 7: 4655
- 8 Miyajima R, Ooe Y, Miura T, Ikoma T, Iwamoto H, Takizawa S, Hasegawa E. J. Am. Chem. Soc. 2023; 145: 10236
- 9 Miyajima R, Kiuchi T, Ooe Y, Iwamoto H, Takizawa S, Hasegawa E. J. Photochem. Photobiol. 2023; 16: 100195
- 10a Henderson AR. P, Kosowan JR, Wood TE. Can. J. Chem. 2017; 95: 483
- 10b Holden CM, Greaney MF. Chem. Eur. J. 2017; 23: 8992
- 11a Huynh M, De Abreu M, Belmont P, Brachet E. Chem. Eur. J. 2021; 27: 3581
- 11b Allen AR, Noten EA, Stephenson CR. J. Chem. Rev. 2022; 122: 2695
- 12 Li Y, Hu B, Dong W, Xie X, Wan J, Zhang Z. J. Org. Chem. 2016; 81: 7036
- 13 Hasegawa E, Yoshioka N, Tanaka T, Nakaminato T, Oomori K, Ikoma T, Iwamoto H, Wakamatsu K. ACS Omega 2020; 5: 7651
- 14 Typical Reaction Procedures (a) Reaction of 2b Utilizing 1e-H (Scheme [4]) A solution of 2b (41.7 mg, 0.10 mmol), 1e-H (58.7 mg, 0.15 mmol), and AcOH (11.5 μL, 0.20 mmol) in N2 pre-purged DMF (2.0 mL) was stirred at room temperature for 1 h. The reaction mixture was worked-up in the manner described in the Supporting Information. No recovery of 2b (conv. 100%) and the yield of 3b (0.070 mmol, 70%) were determined by 1H NMR spectroscopy (Figure S6).(b) Photocatalytic Reaction of 2d Utilizing 1f·ClO4(Scheme [6]) An N2 pre-purged solution of 2d (41.5 mg, 0.10 mmol), 1f·ClO4 (13.0 mg, 0.02 mmol), pic-BH3 (15.1 mg, 0.12 mmol), and AcOH (28.6 μL, 0.50 mmol) in DMF (2.0 mL) was irradiated with Xe lamp at room temperature for 1 h. The photolysate was worked-up in the manner described in the Supporting Information. No recovery of 2d (conv. 100%) and the yield of 3d (0.060 mmol, 60%) were determined by 1H NMR spectroscopy (Figure S14).
- 15 Frisch MJ, Trucks GW, Schlegel HB, Scuseria GE, Robb MA, Cheeseman JR, Scalmani G, Barone V, Petersson GA, Nakatsuji H, Li X, Caricato M, Marenich AV, Bloino J, Janesko BG, Gomperts R, Mennucci B, Hratchian HP, Ortiz JV, Izmaylov AF, Sonnenberg JL, Williams-Young D, Ding F, Lipparini F, Egidi F, Goings J, Peng B, Petrone A, Henderson T, Ranasinghe D, Zakrzewski VG, Gao J, Rega N, Zheng G, Liang W, Hada M, Ehara M, Toyota K, Fukuda R, Hasegawa J, Ishida M, Nakajima T, Honda Y, Kitao O, Nakai H, Vreven T, Throssell K, Montgomery JA. Jr, Peralta JE, Ogliaro F, Bearpark MJ, Heyd JJ, Brothers EN, Kudin KN, Staroverov VN, Keith TA, Kobayashi R, Normand J, Raghavachari K, Rendell AP, Burant JC, Iyengar SS, Tomasi J, Cossi M, Millam JM, Klene M, Adamo C, Cammi R, Ochterski JW, Martin RL, Morokuma K, Farkas O, Foresman JB, Fox DJ. Gaussian 16, Revision C.01. Gaussian, Inc; Wallingford CT (USA): 2016
- 16a Anderse ML, Mathivanan N, Wayner DD. M. J. Am. Chem. Soc. 1996; 118: 4871
- 16b Andrieux CP, Savéant J.-M, Tallec A, Tardivel R, Tardy C. J. Am. Chem. Soc. 1996; 118: 9788
- 16c Andrieux CP, Savéant J.-M, Tallec A, Tardivel R, Tardy C. J. Am. Chem. Soc. 1997; 119: 2420
- 16d Anderse ML, Long W, Wayner DD. M. J. Am. Chem. Soc. 1997; 119: 6590
Corresponding Author
Publication History
Received: 30 May 2023
Accepted after revision: 14 August 2023
Accepted Manuscript online:
14 August 2023
Article published online:
19 September 2023
© 2023. Thieme. All rights reserved
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References and Notes
- 1a Eberson L. Electron Transfer Reactions in Organic Chemistry. Springer; Berlin: 1987
- 1b Photoinduced Electron Transfer, Parts A–D. Fox MA, Chanon M. Elsevier; Amsterdam: 1988
- 1c Advances in Electron Transfer Chemistry, Vol. 1–6. Mariano PS. JAI; Greenwich: 1991
- 1d Kavarnos GJ. Fundamental of Photoinduced Electron Transfer. VCH; New York: 1993
- 1e Connelly NG, Geiger WE. Chem. Rev. 1996; 96: 877
- 1f Electron Transfer in Chemistry, Vol. 1–5. Balzani V. Wiley-VCH; Weinheim: 2001
- 1g Organic Electrochemistry, 4th ed. Lund H, Hammerich O. Marcel Dekker; New York: 2001
- 1h Fukuzumi S. Electron Transfer: Mechanisms and Applications . Wiley-VCH; Weinheim: 2020
- 2a Schmittel M, Burghart A. Angew. Chem., Int. Ed. Engl. 1997; 36: 2550
- 2b Berger DJ, Tanko JM. The Chemistry of Double-Bonded Functional Groups . Patai S. Wiley; New York: 1997: 1281
- 2c Roth HD. Reactive Intermediate Chemistry . Moss RA, Platz MS, Jones MJr. Wiley; Hoboken: 2004: 205
- 2d Todres ZV. Ion-Radical Organic Chemistry Principles and Applications, 2nd ed. CRC Press; Boca Raton: 2009
- 2e Zhang N, Samanta SR, Rosen BM, Percec V. Chem. Rev. 2014; 114: 5848
- 2f Studer A, Curran DP. Nat. Chem. 2014; 6: 765
- 2g Lee KN, Ngai M.-Y. Chem. Commun. 2017; 53: 13093
- 2h Syroeshkin MA, Kuriakose F, Saverina EA, Timofeeva VA, Egorov MP, Alabugin IV. Angew. Chem. Int. Ed. 2019; 58: 5532
- 2i Peter A, Agasti S, Knowles O, Pye E, Procter DJ. Chem. Soc. Rev. 2021; 50: 5349
- 3 Zhu X.-Q, Zhang M.-T, Yu A, Wang C.-H, Cheng J.-P. J. Am. Chem. Soc. 2008; 130: 2501
- 4a Chikashita H, Itoh K. Bull. Chem. Soc. Jpn. 1986; 59: 1747
- 4b Ramos SM, Tarazi M, Wuest JD. J. Org. Chem. 1987; 52: 5437
- 4c Chen J, Tanner DD. J. Org. Chem. 1988; 53: 3897
- 4d Hasegawa E, Kato T, Kitazume T, Yanagi K, Hasegawa K, Horaguchi T. Tetrahedron Lett. 1996; 37: 7079
- 4e Lee I.-SH, Jeoung EH, Kreevoy MM. J. Am. Chem. Soc. 1997; 119: 2722
- 4f Schwarz DE, Cameron TM, Hay PJ, Scott BL, Tumas W, Thorn DL. Chem. Commun. 2005; 5919
- 4g Wei P, Oh JH, Dong G, Bao Z. J. Am. Chem. Soc. 2010; 132: 8852
- 4h Tamaki Y, Koike K, Morimoto T, Ishitani O. J. Catal. 2013; 304: 22
- 4i Horn M, Schappele LH, Lang-Wittkowski G, Mayr H, Ofial AR. Chem. Eur. J. 2013; 19: 249
- 4j Kim SS, Bae S, Jo WH. Chem. Commun. 2015; 51: 17413
- 4k Hasegawa E, Takizawa S. Aust. J. Chem. 2015; 68: 1640
- 4l Zhang Y, Petersen JL, Milsmann CA. J. Am. Chem. Soc. 2016; 138: 13115
- 4m Mehrotra S, Raje S, Jain AK, Angamuthu R. ACS Sustainable Chem. Eng. 2017; 5: 6322
- 4n Iakovenko R, Hlaváč J. Green Chem. 2021; 23: 440
- 4o Tun SL, Mariappan SV. S, Pigge FC. J. Org. Chem. 2022; 87: 8059
- 4p Wang Y.-F, Zhang M.-T. J. Am. Chem. Soc. 2022; 144: 12459
- 5a Ilic S, Alherz A, Musgrave CB, Glusac KD. Chem. Commun. 2019; 55: 5583
- 5b Rohrbach S, Shah RS, Tuttle T, Murphy JA. Angew. Chem. Int. Ed. 2019; 58: 11454
- 5c Kodama T, Kubo M, Shinji W, Ohkubo K, Tobisu M. Chem. Sci. 2020; 11: 12109
- 5d Weerasooriya RB, Drummer MC, Phelan BT, Gesiorski JL, Sprague-Klein EA, Chen LX, Glusac KD. J. Phys. Chem. C 2022; 126: 17816
- 5e Xie W, Xu J, Md Idros U, Katsuhira J, Fuki M, Hayashi M, Yamanaka M, Kobori Y, Matsubara R. Nat. Chem. 2023; 15: 794
- 6a Hasegawa E, Ohta T, Tsuji S, Mori K, Uchida K, Miura T, Ikoma T, Tayama E, Iwamoto H, Takizawa S, Murata S. Tetrahedron 2015; 71: 5494
- 6b Hasegawa E, Nagakura Y, Izumiya N, Matsumoto K, Tanaka T, Miura T, Ikoma T, Iwamoto H, Wakamatsu K. J. Org. Chem. 2018; 83: 10813
- 6c Hasegawa E, Nakamura S, Oomori K, Tanaka T, Iwamoto H, Wakamatsu K. J. Org. Chem. 2021; 86: 2556
- 7a Hasegawa E, Izumiya N, Miura T, Ikoma T, Iwamoto H, Takizawa S, Murata S. J. Org. Chem. 2018; 83: 3921
- 7b Hasegawa E, Tanaka T, Izumiya N, Kiuchi T, Ooe Y, Iwamoto H, Takizawa S, Murata S. J. Org. Chem. 2020; 85: 4344
- 7c Tanaka T, Kiuchi T, Ooe Y, Iwamoto H, Takizawa S, Murata S, Hasegawa E. ACS Omega 2022; 7: 4655
- 8 Miyajima R, Ooe Y, Miura T, Ikoma T, Iwamoto H, Takizawa S, Hasegawa E. J. Am. Chem. Soc. 2023; 145: 10236
- 9 Miyajima R, Kiuchi T, Ooe Y, Iwamoto H, Takizawa S, Hasegawa E. J. Photochem. Photobiol. 2023; 16: 100195
- 10a Henderson AR. P, Kosowan JR, Wood TE. Can. J. Chem. 2017; 95: 483
- 10b Holden CM, Greaney MF. Chem. Eur. J. 2017; 23: 8992
- 11a Huynh M, De Abreu M, Belmont P, Brachet E. Chem. Eur. J. 2021; 27: 3581
- 11b Allen AR, Noten EA, Stephenson CR. J. Chem. Rev. 2022; 122: 2695
- 12 Li Y, Hu B, Dong W, Xie X, Wan J, Zhang Z. J. Org. Chem. 2016; 81: 7036
- 13 Hasegawa E, Yoshioka N, Tanaka T, Nakaminato T, Oomori K, Ikoma T, Iwamoto H, Wakamatsu K. ACS Omega 2020; 5: 7651
- 14 Typical Reaction Procedures (a) Reaction of 2b Utilizing 1e-H (Scheme [4]) A solution of 2b (41.7 mg, 0.10 mmol), 1e-H (58.7 mg, 0.15 mmol), and AcOH (11.5 μL, 0.20 mmol) in N2 pre-purged DMF (2.0 mL) was stirred at room temperature for 1 h. The reaction mixture was worked-up in the manner described in the Supporting Information. No recovery of 2b (conv. 100%) and the yield of 3b (0.070 mmol, 70%) were determined by 1H NMR spectroscopy (Figure S6).(b) Photocatalytic Reaction of 2d Utilizing 1f·ClO4(Scheme [6]) An N2 pre-purged solution of 2d (41.5 mg, 0.10 mmol), 1f·ClO4 (13.0 mg, 0.02 mmol), pic-BH3 (15.1 mg, 0.12 mmol), and AcOH (28.6 μL, 0.50 mmol) in DMF (2.0 mL) was irradiated with Xe lamp at room temperature for 1 h. The photolysate was worked-up in the manner described in the Supporting Information. No recovery of 2d (conv. 100%) and the yield of 3d (0.060 mmol, 60%) were determined by 1H NMR spectroscopy (Figure S14).
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