Efficient Protosilylation of Unsaturated Compounds with Silylboronates over a Heterogeneous Cu₃N Nanocube Catalyst

Abstract

Copper-catalyzed protosilylation of unsaturated compounds with silylboronates has attracted attention for the production of organosilanes; however, the use of organic ligands or bases is unavoidable. Herein, we report a heterogeneous catalytic system for the protosilylation of unsaturated compounds with silylboronates under mild and additive-free conditions over copper nitride nanocubes (Cu₃N NCs). This method can be applied to various substrates (e.g., alkynes, alkenes, or imines) to afford the corresponding organosilicon compounds. The Cu₃N NC catalyst can be easily recovered and reused several times. Thus, the active and reusable Cu₃N NC catalyst offers a green and sustainable method for efficient organosilane production.

Organosilicon compounds are essential building blocks in organic syntheses.[1] [2] Among the available methods for preparing organosilicon compounds, catalytic protosilylation is the most economical and powerful. Several homogeneous transition-metal catalysts have been developed for the protosilylation of unsaturated compounds.[3–9] Cu-catalyzed protosilylation of alkynes,[10–21] alkenes,[12] ^, [22] [23] [24] [25] and imines[26] [27] with silylboronates has been attracting increasing attention, especially during the last ten years (Scheme [1]A).[28] [29] [30] However, the use of base additives or appropriate organic ligands that tune the Lewis acidity of the Cu species is required to promote the reaction efficiently. In addition, difficulties in separating and recycling Cu salts restrict their prospects for industrial application. The development of additive-free and reusable catalytic systems is, therefore, highly desirable for the efficient and environmentally benign protosilylation of unsaturated compounds.

Nanosized metal non-oxides, such as metal nitrides,[31] phosphides,[32] [33] [34] or sulfides, are attractive catalytic materials in organic syntheses.[35–37] We recently reported the development of copper nitride nanocubes (Cu₃N NCs), which served as efficient heterogeneous catalysts for the highly selective borylation of alkynes with bis(pinacolato)diboron (B₂Pin₂) and EtOH under additive-free and mild conditions.[38] In addition, the surface of the Cu₃N NCs has a unique Lewis acid–base property that plays a key role in promoting the borylation of alkynes with B₂Pin₂. Inspired by this finding, we hypothesized that the Cu₃N NC catalyst might be effective in the protosilylation of unsaturated compounds with silylboronates (Scheme [1]B). In this study, we present a heterogeneous Cu-based catalytic system for the synthesis of various silanes through the protosilylation of unsaturated compounds with the pinacol ester of (dimethylphenylsilyl)boronic acid (PhMe₂Si–BPin). Furthermore, Cu₃N NC was used as an efficient catalyst for the conversion of various substrates, including alkynes, alkenes, and imines, into the desired silanes under base- and ligand-free conditions. In addition, the high durability of the Cu₃N NC catalyst was demonstrated by its application in gram-scale reactions and reuse experiments.

Cu₃N NCs were prepared according to our previously reported method [for details, see the Supporting Information (SI)].[38] [39] Powder X-ray diffraction (PXRD) patterns (SI; Figure S1)[40]and representative transmission electron microscopy (TEM) images (Figure [1]) showed the formation of Cu₃N NCs with a cubic structure and an average edge length of 67 nm.

The prepared Cu₃N NCs were used for the protosilylation of phenylacetylene (1a) with PhMe₂Si–BPin (Table [1]),[41] [42] [43] which is a practical method for synthesizing vinylsilanes that are important intermediates in organic syntheses.[10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20] [21] Notably, the Cu₃N NC catalyst effectively promoted this reaction, producing dimethyl(phenyl)[(E)-styryl]silane (2a)[44] in 73% yield (Table [1], entry 1). This is the first reported protosilylation of an alkyne with PhMe₂Si–BPin under additive-free conditions over a heterogeneous Cu-based catalyst. Other Cu-based catalysts (CuI and CuO) were inactive in this reaction (entries 2 and 3, respectively). Increasing the amount of PhMe₂Si–BPin to 1.5 equivalents improved the conversion of 1a, affording a 90% yield of 2a (entry 4). Reuse experiments were conducted to evaluate the durability of the Cu₃N NC catalyst. After the reaction, the Cu₃N NCs were separated from the reaction mixture and reused three times without any significant loss of activity (entry 5, see SI; Figure S3 for details). Moreover, the Cu₃N NC catalytic system was applicable to gram-scale synthesis, giving 2a in 89% isolated yield, with a turnover number (TON) exceeding 894 based on the total number of Cu atoms used in the reaction (SI; Scheme S1). This TON value is greater than that of previously reported Cu-based catalytic systems (SI; Table S1). These results clearly demonstrate the high activity and durability of the Cu₃N NC catalyst.

To demonstrate the applicability of the Cu₃N NC catalytic system, the protosilylation of various alkynes was investigated (Scheme [2]A). The Cu₃N NCs efficiently promoted the protosilylation of aromatic alkynes with electron-donating (e.g., –OMe, –Me, and –NH₂) or electron-withdrawing groups (e.g., –Cl, –F, and –NO₂) substituents (2a–j). In addition, the heterocyclic substrates 3-ethynylthiophene and 3-ethynylpyridine were protosilylated to give the desired products 2k and 2l in yields of 74 and 86%, respectively. This method could also be applied to aliphatic and internal alkynes, giving products 2m–o in moderate yields. Bioactive phthalimide and steroid derivatives were suitable substrates, and the desired products 2p and 2q were obtained in satisfactory yields.

Table 1 Protosilylation of Alkyne 1a with Various Cu-Based Catalysts^a

Entry	Catalyst	Yieldb (%) of 2a
1	Cu3N NCs	73
2	CuI	0
3	CuO	0
4c	Cu3N NCs	90
5c	Cu3N NCs (3rd reuse)	90

^a Reaction conditions: 1a (0.25 mmol), PhMe₂Si–BPin (1.2 equiv, 0.30 mmol), catalyst (Cu: 5 mol%), EtOH (1.0 mL), 30 °C, 1 h, under Ar.

^b By ¹H NMR analysis with 1,4-dinitrobenzene as an internal standard.

^c PhMe₂Si–BPin (1.5 equiv, 0.375 mmol).

Notably, the catalytic double protosilylation of alkynes is a useful and simple method for synthesizing geminal gem-disilylated compounds.[11] ^, [45] [46] [47] Cu₃N NCs exhibited an excellent catalytic activity for the double protosilylation of terminal alkynes with electron-withdrawing groups, and the desired gem-disilylated products 2r and 2s were formed in good yields. This is the first report on the synthesis of gem-disilylated compounds over a heterogeneous metal catalyst.

The protosilylation of alkenes with electron-withdrawing groups was then examined (Scheme [2]B). Butyl acrylate underwent β-silylation to produce 3a in 99% yield. Acrylonitrile was effectively silylated to 3b in 83% yield. The protosilylation of diethyl vinylphosphonate proceeded well to afford 3c [48] in 84% yield, although a reported Cu-based catalytic system was inactive for this substrate.[22] Phenyl vinyl sulfone was converted into the β-silyl sulfone 3d in 79% yield. Furthermore, the protosilylation of cyclic ketones was conducted, and the corresponding silanes 3e and 3f were obtained in excellent yields. Interestingly, ethyl buta-2,3-dienoate as an allene was readily protosilylated to afford the desired product 3g.[49] [50] In addition, N,N-dimethylacrylamide was a suitable substrate for the reaction, giving 3h in 89% yield. Notably, this method could be used for the late-stage functionalization of naturally occurring compounds such as (E)-chalcone, sesamol, and estrone, providing the corresponding protosilylated products 3i–k in excellent yields.[51] This is the first example of a heterogeneous catalyst that promotes the protosilylation of alkenes and allenes with PhMe₂Si–BPin.

Subsequently, the protosilylation of imines was investigated (Scheme [2]C). Various imines were efficiently protosilylated using the Cu₃N NC catalytic system to afford the desired silanes 4a–d in yields of 67–80%. In addition, the reaction of azobenzene with PhMe₂Si–BPin was examined; however, the undesired product 1,2-diphenylhydrazine was obtained in 89% yield (see SI; Scheme S3 for details). Silylamine might be formed during the reaction and protonated in EtOH to afford the 1,2-diphenylhydrazine. Overall, these results demonstrate the high catalytic performance of Cu₃N NCs in the protosilylation of various unsaturated compounds.

We previously reported that the surface of the Cu₃N NC catalyst possesses Lewis acid–base sites that play vital roles in the borylation of alkynes with B₂Pin₂.[38] Based on this knowledge, we propose a mechanism for the efficient Cu₃N NC-catalyzed protosilylation of 1a (SI; Scheme S4). Initially, ethanol (EtOH) is activated at the basic sites of the Cu₃N NC catalyst and reacts with PhMe₂Si–BPin to generate the Cu–Si and EtO–BPin species. The absorption of 1a onto the Cu sites, followed by the reaction with the Cu–Si species, forms an addition intermediate. Finally, the desired product is produced by hydrogen transfer to the Cu intermediate, and the Cu₃N NC catalyst is regenerated. The above reaction pathway was confirmed by the following experimental results. First, EtO–BPin was detected by GC–MS (SI; Figures S4 and S5), and secondly, when the reaction was performed in monodeuterized ethanol (EtOD), monodeuterized 2a (2a-d) formed as the main product, indicating the participation of EtOH in the reaction (SI; Scheme S5). Therefore, the excellent catalytic activity of the Cu₃N NCs is attributed to their unique reactivity toward EtOH, PhMe₂Si–BPin, and unsaturated compounds.

In conclusion, we have developed an efficient method for synthesizing various silanes through the Cu₃N NC-catalyzed protosilylation of unsaturated compounds. Various substrates, such as alkynes, alkenes, and imines, were successfully transformed into the corresponding organosilanes under additive-free conditions. In addition, the Cu₃N NC catalyst was used for the double protosilylation of alkynes with electron-withdrawing groups to produce gem-disilylated products. The synthetic utility of this protocol was demonstrated through reuse experiments and by a gram-scale synthesis of a vinylic silane. This paper presents, for the first time, the protosilylation of various unsaturated compounds over a heterogeneous Cu-based catalyst. These findings will contribute significantly to the development of green and sustainable technologies for the production of valuable silanes.

Conflict of Interest

The authors declare no conflict of interest.

Acknowledgment

We thank Dr. Toshiaki Ina and Dr. Tetsuo Honma (SPring-8) for the X-ray absorption fine-structure measurements (grant nos. 2022B1585, 2022B1699, 2022B0586, and 2023A1896). This study was the result of the use of the research equipment shared by the MEXT Project to promote the public utilization of advanced research infrastructure based on the program for supporting the construction of core facilities (grant nos. JPMXS0441200022 and JPMXS0441200023).

• References and Notes

• 1 Nakao Y, Hiyama T. Chem. Soc. Rev. 2011; 40: 4893
  CrossrefPubMedSearch in Google Scholar
• 2 Ojima I, Li Z, Zhu J. In The Chemistry of Organic Silicon Compounds, Vol. 2, Chap. 29. Wiley; Chichester: 1998: 1687
  CrossrefSearch in Google Scholar
• 3 Comprehensive Handbook on Hydrosilylation. Marciniec B. Pergamon; Oxford: 1992
  Search in Google Scholar
• 4 Troegel D, Stohrer J. Coord. Chem. Rev. 2011; 255: 1440
  CrossrefSearch in Google Scholar
• 5 Du X, Huang Z. ACS Catal. 2017; 7: 1227
  CrossrefSearch in Google Scholar
• 6 Obligacion JV, Chirik PJ. Nat. Rev. Chem. 2018; 2: 15
  CrossrefPubMedSearch in Google Scholar
• 7 Tamang SR, Findlater M. Molecules 2019; 24: 3194
  CrossrefPubMedSearch in Google Scholar
• 8 Naganawa Y, Inomata K, Sato K, Nakajima Y. Tetrahedron Lett. 2020; 61: 151513
  CrossrefSearch in Google Scholar
• 9 He P, Hu M.-Y, Zhang X.-Y, Zhu S.-F. Synthesis 2022; 54: 49
  Thieme ConnectSearch in Google Scholar
• 10 Wang P, Yeo X.-L, Loh T.-P. J. Am. Chem. Soc. 2011; 133: 1254
  CrossrefPubMedSearch in Google Scholar
• 11 Gao L, Zhang Y, Song Z. Synlett 2013; 24: 139
  Search in Google Scholar
• 12 Meng F, Jang H, Hoveyda AH. Chem. Eur. J. 2013; 19: 3204
  CrossrefPubMedSearch in Google Scholar
• 13 Zhou H, Wang Y.-B. ChemCatChem 2014; 6: 2512
  CrossrefSearch in Google Scholar
• 14 Hazra CK, Fopp C, Oestreich M. Chem. Asian J. 2014; 9: 3005
  CrossrefPubMedSearch in Google Scholar
• 15 Calderone JA, Santos WL. Angew. Chem. Int. Ed. 2014; 53: 4154
  CrossrefPubMedSearch in Google Scholar
• 16 Linstadt RT. H, Peterson CA, Lippincott DJ, Jette CI, Lipshutz BH. Angew. Chem. Int. Ed. 2014; 53: 4159
  CrossrefPubMedSearch in Google Scholar
• 17 García-Rubia A, Romero-Revilla JA, Mauleón P, Gómez Arrayás R, Carretero JC. J. Am. Chem. Soc. 2015; 137: 6857
  CrossrefPubMedSearch in Google Scholar
• 18 Xuan Q.-Q, Ren C.-L, Liu L, Wang D, Li C.-J. Org. Biomol. Chem. 2015; 13: 5871
  CrossrefPubMedSearch in Google Scholar
• 19 Meng F.-F, Xie J.-H, Xu Y.-H, Loh T.-P. ACS Catal. 2018; 8: 5306
  CrossrefPubMedSearch in Google Scholar
• 20 Zhao M, Shan C.-C, Wang Z.-L, Yang C, Fu Y, Xu Y.-H. Org. Lett. 2019; 21: 6016
  CrossrefPubMedSearch in Google Scholar
• 21 Gao Y, Yazdani S, Kendrick A, Junor GP, Kang T, Grotjahn DB, Bertrand G, Jazzar R, Engle KM. Angew. Chem. Int. Ed. 2021; 60: 19871
  CrossrefPubMedSearch in Google Scholar
• 22 Calderone JA, Santos WL. Org. Lett. 2012; 14: 2090
  CrossrefPubMedSearch in Google Scholar
• 23 Xuan Q.-Q, Zhong N.-J, Ren C.-L, Liu L, Wang D, Chen Y.-J, Li C.-J. J. Org. Chem. 2013; 78: 11076
  CrossrefPubMedSearch in Google Scholar
• 24 Kitanosono T, Zhu L, Liu C, Xu P, Kobayashi S. J. Am. Chem. Soc. 2015; 137: 15422
  CrossrefPubMedSearch in Google Scholar
• 25 Plotzitzka J, Kleeberg C. Inorg. Chem. 2016; 55: 4813
  CrossrefPubMedSearch in Google Scholar
• 26 Grirrane A, Corma A, García H. Science 2008; 322: 1661
  CrossrefPubMedSearch in Google Scholar
• 27 Vyas DJ, Fröhlich R, Oestreich M. Org. Lett. 2011; 13: 2094
  CrossrefPubMedSearch in Google Scholar
• 28 Tsuji Y, Fujihara T. Chem. Rec. 2016; 16: 2294
  CrossrefPubMedSearch in Google Scholar
• 29 Fujihara T, Tsuji Y. Synthesis 2018; 50: 1737
  Thieme ConnectSearch in Google Scholar
• 30 Feng J.-J, Mao W, Zhang L, Oestreich M. Chem. Soc. Rev. 2021; 50: 2010
  CrossrefPubMedSearch in Google Scholar
• 31 Xu H, Yamaguchi S, Mitsudome T, Mizugaki T. Org. Biomol. Chem. 2021; 19: 6593
  CrossrefPubMedSearch in Google Scholar
• 32 Fujita S, Nakajima K, Yamasaki J, Mizugaki T, Jitsukawa K, Mitsudome T. ACS Catal. 2020; 10: 4261
  CrossrefSearch in Google Scholar
• 33 Yamaguchi S, Fujita S, Nakajima K, Yamazoe S, Yamasaki J, Mizugaki T, Mitsudome T. Green Chem. 2021; 23: 2010
  CrossrefSearch in Google Scholar
• 34 Ishikawa H, Nakatani N, Yamaguchi S, Mizugaki T, Mitsudome T. ACS Catal. 2023; 13: 5744
  CrossrefSearch in Google Scholar
• 35 Carenco S, Portehault D, Boissière C, Mérzailles N, Sanchez C. Chem. Rev. 2013; 113: 7981
  CrossrefPubMedSearch in Google Scholar
• 36 Gao Q, Liu N, Wang S, Tang Y. Nanoscale 2014; 6: 14106
  CrossrefPubMedSearch in Google Scholar
• 37 Aireddy DR, Ding K. ACS Catal. 2022; 12: 4707
  CrossrefSearch in Google Scholar
• 38 Xu H, Yamaguchi S, Mitsudome T, Mizugaki T. Org. Biomol. Chem. 2023; 21: 1404
  CrossrefPubMedSearch in Google Scholar
• 39 Xu H, Yamaguchi S, Mitsudome T, Mizugaki T. Eur. J. Org. Chem. 2022; 2022: e202200826
  CrossrefSearch in Google Scholar
• 40 Deshmukh R, Zeng G, Tervoort E, Staniuk M, Wood D, Niederberger M. Chem. Mater. 2015; 27: 8282
  CrossrefSearch in Google Scholar
• 41 Suginome M, Nakamura H, Ito Y. Angew. Chem. Int. Ed. 1997; 36: 2516
  CrossrefSearch in Google Scholar
• 42 Suginome M, Matsuda T, Yoshimoto T, Ito Y. Org. Lett. 1999; 1: 1567
  CrossrefPubMedSearch in Google Scholar
• 43 Ohmura T, Taniguchi H, Suginome M. J. Am. Chem. Soc. 2006; 128: 13682
  CrossrefPubMedSearch in Google Scholar
• 44 Dimethyl(phenyl)[(E)-styryl]silane (2a); Typical Procedure
  1a (25.5 mg, 0.25 mmol), PhMe₂Si–BPin (78.7 mg, 0.30 mmol), Cu₃N NCs (2.5 mg, 5 mol%), and EtOH (1.0 mL) were mixed sequentially, and the resulting mixture was vigorously stirred at 30 °C for 1 h under Ar. The mixture was then concentrated in vacuo, and the residue was purified by flash chromatography (silica gel, hexane–EtOAc) to give a colorless oil; yield: 43.6 mg (0.183 mmol, 73%). ¹H NMR (400 MHz, CDCl₃): δ = 7.60–7.55 (m, 2 H), 7.45–7.42 (m, 2 H), 7.38–7.27 (m, 5 H), 7.30–7.22 (m, 1 H), 6.94 (d, J = 19.2 Hz, 1 H), 6.62 (d, J = 19.2 Hz, 1 H), 0.43 (s, 6 H). ¹³C NMR (100 MHz, CDCl₃): δ = 145.5, 138.7, 138.3, 134.1, 129.2, 128.7, 128.3, 128.0, 127.2, 126.7, –2.4.
• 45 Hu M.-Y, Lian J, Sun W, Qiao T.-Z, Zhu S.-F. J. Am. Chem. Soc. 2019; 141: 4579
  CrossrefPubMedSearch in Google Scholar
• 46 Chen W, Song H, Li J, Cui C. Angew. Chem. Int. Ed. 2020; 59: 2365
  CrossrefPubMedSearch in Google Scholar
• 47 Wang G, Su X, Gao L, Liu X, Li G, Li S. Chem. Sci. 2021; 12: 10883
  CrossrefPubMedSearch in Google Scholar
• 48 Diethyl {2-[dimethyl(phenyl)silyl]ethyl}phosphonate (3c); Typical Procedure Diethyl vinylphosphonate (41.0 mg, 0.25 mmol), PhMe₂Si–BPin (98.3 mg, 0.375 mmol), Cu₃N NCs (2.5 mg, 5 mol%), and EtOH (1.0 mL) were mixed sequentially, and the resulting mixture was vigorously stirred at 30 °C for 12 h under Ar. The mixture was concentrated in vacuo, and the residue was purified by flash chromatography (silica gel, hexane–EtOAc) to give a colorless oil; yield: 63.0 mg (0.21 mmol, 84%). IR (ATR): 2977, 1414, 1236, 1019, 952, 806, 725, 702, 466 cm^–1. ¹H NMR (400 MHz, CDCl₃): δ = 7.51–7.46 (m, 2 H), 7.39–7.32 (m, 3 H), 4.15–4.01 (m, 4 H), 1.68–1.57 (m, 2 H), 1.30 (t, J = 7.2 Hz, 6 H), 1.05–0.93 (m, 2 H), 0.29 (s, 6 H). ¹³C NMR (100 MHz, CDCl3): δ = 137.8, 133.6, 129.3, 128.0, 61.6 (d, J = 7.0 Hz), 20.5, 19.1, 16.5 (d, J = 6.0 Hz), 7.5 (d, J = 9.0 Hz), –3.5. HRMS (ESI): m/z [M⁺] calcd for C₁₄H₂₅O₃PSi: 300.1296; found: 300.1311.
• 49 Xu Y.-H, Wu L.-H, Wang J, Loh T.-P. Chem Commun. 2014; 50: 7195
  CrossrefPubMedSearch in Google Scholar
• 50 Pashikanti S, Calderone JA, Nguyen MK, Sibley CD, Santos WL. Org. Lett. 2016; 18: 2443
  CrossrefPubMedSearch in Google Scholar
• 51 The protosilylation of simple aliphatic or aromatic alkenes such as hex-1-ene and styrene was investigated; however, the corresponding silanes were not obtained (see SI; Scheme S2).

Corresponding Author

Publication History

Received: 20 September 2023

Accepted after revision: 13 October 2023

Accepted Manuscript online:
13 October 2023

Article published online:
17 November 2023

© 2023. Thieme. All rights reserved

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany

• References and Notes

• 1 Nakao Y, Hiyama T. Chem. Soc. Rev. 2011; 40: 4893
  CrossrefPubMedSearch in Google Scholar
• 2 Ojima I, Li Z, Zhu J. In The Chemistry of Organic Silicon Compounds, Vol. 2, Chap. 29. Wiley; Chichester: 1998: 1687
  CrossrefSearch in Google Scholar
• 3 Comprehensive Handbook on Hydrosilylation. Marciniec B. Pergamon; Oxford: 1992
  Search in Google Scholar
• 4 Troegel D, Stohrer J. Coord. Chem. Rev. 2011; 255: 1440
  CrossrefSearch in Google Scholar
• 5 Du X, Huang Z. ACS Catal. 2017; 7: 1227
  CrossrefSearch in Google Scholar
• 6 Obligacion JV, Chirik PJ. Nat. Rev. Chem. 2018; 2: 15
  CrossrefPubMedSearch in Google Scholar
• 7 Tamang SR, Findlater M. Molecules 2019; 24: 3194
  CrossrefPubMedSearch in Google Scholar
• 8 Naganawa Y, Inomata K, Sato K, Nakajima Y. Tetrahedron Lett. 2020; 61: 151513
  CrossrefSearch in Google Scholar
• 9 He P, Hu M.-Y, Zhang X.-Y, Zhu S.-F. Synthesis 2022; 54: 49
  Thieme ConnectSearch in Google Scholar
• 10 Wang P, Yeo X.-L, Loh T.-P. J. Am. Chem. Soc. 2011; 133: 1254
  CrossrefPubMedSearch in Google Scholar
• 11 Gao L, Zhang Y, Song Z. Synlett 2013; 24: 139
  Search in Google Scholar
• 12 Meng F, Jang H, Hoveyda AH. Chem. Eur. J. 2013; 19: 3204
  CrossrefPubMedSearch in Google Scholar
• 13 Zhou H, Wang Y.-B. ChemCatChem 2014; 6: 2512
  CrossrefSearch in Google Scholar
• 14 Hazra CK, Fopp C, Oestreich M. Chem. Asian J. 2014; 9: 3005
  CrossrefPubMedSearch in Google Scholar
• 15 Calderone JA, Santos WL. Angew. Chem. Int. Ed. 2014; 53: 4154
  CrossrefPubMedSearch in Google Scholar
• 16 Linstadt RT. H, Peterson CA, Lippincott DJ, Jette CI, Lipshutz BH. Angew. Chem. Int. Ed. 2014; 53: 4159
  CrossrefPubMedSearch in Google Scholar
• 17 García-Rubia A, Romero-Revilla JA, Mauleón P, Gómez Arrayás R, Carretero JC. J. Am. Chem. Soc. 2015; 137: 6857
  CrossrefPubMedSearch in Google Scholar
• 18 Xuan Q.-Q, Ren C.-L, Liu L, Wang D, Li C.-J. Org. Biomol. Chem. 2015; 13: 5871
  CrossrefPubMedSearch in Google Scholar
• 19 Meng F.-F, Xie J.-H, Xu Y.-H, Loh T.-P. ACS Catal. 2018; 8: 5306
  CrossrefPubMedSearch in Google Scholar
• 20 Zhao M, Shan C.-C, Wang Z.-L, Yang C, Fu Y, Xu Y.-H. Org. Lett. 2019; 21: 6016
  CrossrefPubMedSearch in Google Scholar
• 21 Gao Y, Yazdani S, Kendrick A, Junor GP, Kang T, Grotjahn DB, Bertrand G, Jazzar R, Engle KM. Angew. Chem. Int. Ed. 2021; 60: 19871
  CrossrefPubMedSearch in Google Scholar
• 22 Calderone JA, Santos WL. Org. Lett. 2012; 14: 2090
  CrossrefPubMedSearch in Google Scholar
• 23 Xuan Q.-Q, Zhong N.-J, Ren C.-L, Liu L, Wang D, Chen Y.-J, Li C.-J. J. Org. Chem. 2013; 78: 11076
  CrossrefPubMedSearch in Google Scholar
• 24 Kitanosono T, Zhu L, Liu C, Xu P, Kobayashi S. J. Am. Chem. Soc. 2015; 137: 15422
  CrossrefPubMedSearch in Google Scholar
• 25 Plotzitzka J, Kleeberg C. Inorg. Chem. 2016; 55: 4813
  CrossrefPubMedSearch in Google Scholar
• 26 Grirrane A, Corma A, García H. Science 2008; 322: 1661
  CrossrefPubMedSearch in Google Scholar
• 27 Vyas DJ, Fröhlich R, Oestreich M. Org. Lett. 2011; 13: 2094
  CrossrefPubMedSearch in Google Scholar
• 28 Tsuji Y, Fujihara T. Chem. Rec. 2016; 16: 2294
  CrossrefPubMedSearch in Google Scholar
• 29 Fujihara T, Tsuji Y. Synthesis 2018; 50: 1737
  Thieme ConnectSearch in Google Scholar
• 30 Feng J.-J, Mao W, Zhang L, Oestreich M. Chem. Soc. Rev. 2021; 50: 2010
  CrossrefPubMedSearch in Google Scholar
• 31 Xu H, Yamaguchi S, Mitsudome T, Mizugaki T. Org. Biomol. Chem. 2021; 19: 6593
  CrossrefPubMedSearch in Google Scholar
• 32 Fujita S, Nakajima K, Yamasaki J, Mizugaki T, Jitsukawa K, Mitsudome T. ACS Catal. 2020; 10: 4261
  CrossrefSearch in Google Scholar
• 33 Yamaguchi S, Fujita S, Nakajima K, Yamazoe S, Yamasaki J, Mizugaki T, Mitsudome T. Green Chem. 2021; 23: 2010
  CrossrefSearch in Google Scholar
• 34 Ishikawa H, Nakatani N, Yamaguchi S, Mizugaki T, Mitsudome T. ACS Catal. 2023; 13: 5744
  CrossrefSearch in Google Scholar
• 35 Carenco S, Portehault D, Boissière C, Mérzailles N, Sanchez C. Chem. Rev. 2013; 113: 7981
  CrossrefPubMedSearch in Google Scholar
• 36 Gao Q, Liu N, Wang S, Tang Y. Nanoscale 2014; 6: 14106
  CrossrefPubMedSearch in Google Scholar
• 37 Aireddy DR, Ding K. ACS Catal. 2022; 12: 4707
  CrossrefSearch in Google Scholar
• 38 Xu H, Yamaguchi S, Mitsudome T, Mizugaki T. Org. Biomol. Chem. 2023; 21: 1404
  CrossrefPubMedSearch in Google Scholar
• 39 Xu H, Yamaguchi S, Mitsudome T, Mizugaki T. Eur. J. Org. Chem. 2022; 2022: e202200826
  CrossrefSearch in Google Scholar
• 40 Deshmukh R, Zeng G, Tervoort E, Staniuk M, Wood D, Niederberger M. Chem. Mater. 2015; 27: 8282
  CrossrefSearch in Google Scholar
• 41 Suginome M, Nakamura H, Ito Y. Angew. Chem. Int. Ed. 1997; 36: 2516
  CrossrefSearch in Google Scholar
• 42 Suginome M, Matsuda T, Yoshimoto T, Ito Y. Org. Lett. 1999; 1: 1567
  CrossrefPubMedSearch in Google Scholar
• 43 Ohmura T, Taniguchi H, Suginome M. J. Am. Chem. Soc. 2006; 128: 13682
  CrossrefPubMedSearch in Google Scholar
• 44 Dimethyl(phenyl)[(E)-styryl]silane (2a); Typical Procedure
  1a (25.5 mg, 0.25 mmol), PhMe₂Si–BPin (78.7 mg, 0.30 mmol), Cu₃N NCs (2.5 mg, 5 mol%), and EtOH (1.0 mL) were mixed sequentially, and the resulting mixture was vigorously stirred at 30 °C for 1 h under Ar. The mixture was then concentrated in vacuo, and the residue was purified by flash chromatography (silica gel, hexane–EtOAc) to give a colorless oil; yield: 43.6 mg (0.183 mmol, 73%). ¹H NMR (400 MHz, CDCl₃): δ = 7.60–7.55 (m, 2 H), 7.45–7.42 (m, 2 H), 7.38–7.27 (m, 5 H), 7.30–7.22 (m, 1 H), 6.94 (d, J = 19.2 Hz, 1 H), 6.62 (d, J = 19.2 Hz, 1 H), 0.43 (s, 6 H). ¹³C NMR (100 MHz, CDCl₃): δ = 145.5, 138.7, 138.3, 134.1, 129.2, 128.7, 128.3, 128.0, 127.2, 126.7, –2.4.
• 45 Hu M.-Y, Lian J, Sun W, Qiao T.-Z, Zhu S.-F. J. Am. Chem. Soc. 2019; 141: 4579
  CrossrefPubMedSearch in Google Scholar
• 46 Chen W, Song H, Li J, Cui C. Angew. Chem. Int. Ed. 2020; 59: 2365
  CrossrefPubMedSearch in Google Scholar
• 47 Wang G, Su X, Gao L, Liu X, Li G, Li S. Chem. Sci. 2021; 12: 10883
  CrossrefPubMedSearch in Google Scholar
• 48 Diethyl {2-[dimethyl(phenyl)silyl]ethyl}phosphonate (3c); Typical Procedure Diethyl vinylphosphonate (41.0 mg, 0.25 mmol), PhMe₂Si–BPin (98.3 mg, 0.375 mmol), Cu₃N NCs (2.5 mg, 5 mol%), and EtOH (1.0 mL) were mixed sequentially, and the resulting mixture was vigorously stirred at 30 °C for 12 h under Ar. The mixture was concentrated in vacuo, and the residue was purified by flash chromatography (silica gel, hexane–EtOAc) to give a colorless oil; yield: 63.0 mg (0.21 mmol, 84%). IR (ATR): 2977, 1414, 1236, 1019, 952, 806, 725, 702, 466 cm^–1. ¹H NMR (400 MHz, CDCl₃): δ = 7.51–7.46 (m, 2 H), 7.39–7.32 (m, 3 H), 4.15–4.01 (m, 4 H), 1.68–1.57 (m, 2 H), 1.30 (t, J = 7.2 Hz, 6 H), 1.05–0.93 (m, 2 H), 0.29 (s, 6 H). ¹³C NMR (100 MHz, CDCl3): δ = 137.8, 133.6, 129.3, 128.0, 61.6 (d, J = 7.0 Hz), 20.5, 19.1, 16.5 (d, J = 6.0 Hz), 7.5 (d, J = 9.0 Hz), –3.5. HRMS (ESI): m/z [M⁺] calcd for C₁₄H₂₅O₃PSi: 300.1296; found: 300.1311.
• 49 Xu Y.-H, Wu L.-H, Wang J, Loh T.-P. Chem Commun. 2014; 50: 7195
  CrossrefPubMedSearch in Google Scholar
• 50 Pashikanti S, Calderone JA, Nguyen MK, Sibley CD, Santos WL. Org. Lett. 2016; 18: 2443
  CrossrefPubMedSearch in Google Scholar
• 51 The protosilylation of simple aliphatic or aromatic alkenes such as hex-1-ene and styrene was investigated; however, the corresponding silanes were not obtained (see SI; Scheme S2).

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