An Aluminum Dihydride Working as a Catalyst in Hydroboration and Dehydrocoupling

作者:Yang, Zhi*; Zhong, Mingdong; Ma, Xiaoli; Nijesh, Karikkeeriyil; De, Susmita; Parameswaran, Pattiyil*; Roesky, Herbert W.*
来源:Journal of the American Chemical Society, 2016, 138(8): 2548-2551.
DOI:10.1021/jacs.6b00032

摘要

The well-defined aluminum dihydride LAlH2 (L = HC(CMeNAr)(2), Ar = 2,6-Et2C6H3) (1) operates in catalysis like a transition metal complex. The catalytic activity of 1 for hydroboration of terminal alkynes was investigated. Furthermore, catalyst 1 effectively initiated the dehydrocoupling of boranes with amines, thiols, and phenols, respectively, to form compounds with B-E bonds (E = S, O) under elimination of H-2. Quantum mechanical calculations indicate that hydroboration and dehydrocoupling reactions occur via three consecutive cycloaddition reactions involving the activation of the X-H (X = Al, B, C, and O) sigma-bonds.