Mononuclear Heteroscorpionate Zwitterionic Zinc Terminal Hydride: Synthesis, Reactivity, and Catalysis for Hydrosilylation of Aldehydes

Abstract

Treatment of heteroscorpionate zinc benzyloxy complex LZnOBn (1, L = ( Me Pz) 2 CP(Ph) 2 NPh, Me Pz = 3,5-dimethylpyrazolyl) with phenylsilane (PhSiH 3 ) gave a zinc hydride complex LZnH (2) containing a rare terminal hydride fragment. X-ray diffraction analysis and the DFT calculation confirm the zwitterionic structure of complex 2. The stoichiometric reaction of 2 with CS 2 readily afforded a dithioformate complex LZnSCH(S) (3) of the CS insertion into the Zn−H product. Moreover, complex 2 was an efficient catalyst for the hydrosilylation reaction of a series of silanes and aldehydes under mild conditions, featuring excellent functional group tolerance. The preliminary mechanistic study revealed that both zinc benzyloxy complex 1 and zinc hydride complex 2 were involved in the hydrosilylation process as the reaction intermediates.

Zinc‐Catalyzed Hydrosilylation Copolymerization of Aromatic Dialdehydes with Diphenylsilane

“…Heteroscorpionate zinc hydride complex 1 (Chart S1, Supporting Information) was identified as an efficient catalyst in the hydrosilylation of aldehyde at room temperature without any byproduct or change of pH value . The reaction conditions were rather mild to inhibit any side reactions and the catalyst exhibited excellent tolerance to the functiontional groups.…”

Hydroboration of CO2 catalyzed by heteroscorpionate zwitterionic zinc and magnesium hydride complexes

“…based catalysts are highly desirable. [11][12][13][14] For example, Gerard Parkin et al reported that {[κ 3 -Tptm]M}[HB(C 6 F 5 ) 3 ] catalytic systems could efficiently catalyze a CO 2 hydrosilylation reaction, in which a magnesium-based complex showed efficient capability for the CO 2 reduction reaction. 15 Catalytic hydroboration of CO 2 is an alternative method for efficiently transforming CO 2 to valuable compounds.…”

Cationic Zinc Hydride Catalyzed Carbon Dioxide Reduction to Formate: Deciphering Elementary Reactions, Isolation of Intermediates, and Computational Investigations

“…Molecular zinc compounds have received prominence as reagents for the reduction of unsaturated bonds. [1][2][3][4] They are employedi nt he reduction of olefins, [5][6][7][8] imines, [9][10][11] aldehydes, ketones, [12][13][14][15][16][17][18] and carbond ioxide. [19][20][21][22][23][24][25][26][27][28][29][30] Catalyticr eductiono f carbon dioxide through catalytic hydrosilylation [31][32][33][34] and, to some extent, hydroboration [35,36] with zinc catalysts has been investigated.…”