State Key Laboratory of Elemento-Organic Chemistry and College of Chemistry, Nankai University, Tianjin 300071, People's Republic of China.
J Am Chem Soc. 2021 Aug 25;143(33):12913-12918. doi: 10.1021/jacs.1c04689. Epub 2021 Aug 13.
Allenes are versatile synthons in organic synthesis and medicinal chemistry because of their diverse reactivities. Catalytic 1,4-hydrosilylation of 1,3-enynes may present the straightforward strategy for synthesis of silylallenes. However, the transition-metal-catalyzed reaction has not been successful due to poor selectivity and very limited substrate scopes. We report here the efficient and selective 1,4-hydrosilylation of branched 1,3-enynes enabled by the ene-diamido rare-earth ate catalysts using both alkyl and aryl hydrosilanes, leading to the exclusive formation of tetrasubstituted silylallenes. Deuteration reaction, kinetic study, and DFT calculations were conducted to investigate the possible mechanism, revealing crucial roles of high Lewis acidity, large ionic radius, and ate structure of the rare-earth catalysts.
烯丙基是有机合成和药物化学中多功能的合成子，因为它们具有多样的反应性。1,3-烯炔的催化 1,4-硅氢化可能是合成硅烯丙基的直接策略。然而，由于选择性差和底物范围非常有限，过渡金属催化的反应尚未成功。我们在此报告了通过烯-二酰胺稀土原子转移催化剂，使用烷基和芳基硅烷，有效地、选择性地对支化的 1,3-烯炔进行 1,4-硅氢化，从而得到四取代的硅烯丙基。氘代反应、动力学研究和 DFT 计算被用来研究可能的机理，揭示了稀土催化剂的高路易斯酸度、大离子半径和原子转移结构的关键作用。
