42451-53-6Relevant articles and documents
An N-Heterocyclic Carbene with a Saturated Backbone and Spatially-Defined Steric Impact
Laidlaw, Gillian,Wood, Susanna H.,Kennedy, Alan R.,Nelson, David J.
, p. 105 - 112 (2019)
The synthesis and coordination chemistry of a saturated analogue of a “bulky-yet-flexible” N-heterocyclic carbene (NHC) ligand are described. “SIPaul” is a 4,5-dihydroimidazol-2-ylidene ligand with unsymmetrical aryl N-substituents, and is one of the grow
Reversible Silylium Transfer between P-H and Si-H Donors
Belli, Roman G.,Pantazis, Dimitrios A.,McDonald, Robert,Rosenberg, Lisa
supporting information, p. 2379 - 2384 (2020/12/07)
The Mo=PR2 π* orbital in a Mo phosphenium complex acts as acceptor in a new PIII-based Lewis superacid. This Lewis acid (LA) participates in electrophilic Si-H abstraction from E3SiH to give a Mo-bound secondary phosphine ligand, Mo-PR2H. The resulting Et3Si+ ion remains associated with the Mo complex, stabilized by η1-P-H donation, yet undergoes rapid exchange with an η1-Si-H adduct of free silane in solution. The equilibrium between these two adducts presents an opportunity to assess the role of this new LA in catalytic reactions of silanes: is the LA acting as a catalyst or as an initiator? Preliminary results suggest that a cycle including the Mo-bound phosphine-silylium adduct dominates in the catalytic hydrosilylation of acetophenone, relative to a putative cycle involving the silane-silylium adduct or “free” silylium.
Electrophilic Organobismuth Dication Catalyzes Carbonyl Hydrosilylation
Kannan, Ramkumar,Balasubramaniam, Selvakumar,Kumar, Sandeep,Chambenahalli, Raju,Jemmis, Eluvathingal D.,Venugopal, Ajay
supporting information, p. 12717 - 12721 (2020/09/09)
Bismuth compounds are gaining importance as potential alternatives to transition-metal complexes and electron deficient lighter p-block compounds in homogeneous catalysis. Computational analysis on the two-coordinate [(Me2NC6H4)Bi]2+ possessing three electrophilic sites is experimentally evidenced by the isolation of [{Me2NC6H4}Bi{OP(NMe2)3}3][B(3,5-C6H3Cl2)4]2. These observations led us to generate dicationic organobismuth catalyst, [(Me2NC6H4)Bi(L)3]2+ (L=aldehyde/ketone), evidenced by NMR spectroscopy in solution and by single-crystal X-ray diffraction in the solid state. It efficiently catalyzes hydrosilylation of aldehydes and ketones resulting in silyl ethers as the only products in high yields. Our investigations support a carbonyl activation mechanism at the bismuth center followed by Si?H addition.
