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A unified survey of Si-H and H-H bond activation catalysed by electron-deficient boranes

Oestreich, Martin; Hermeke, Julia; Mohr, Jens

The bond activation chemistry of B(C6F5)(3) and related electron-deficient boranes is currently experiencing a renaissance due to the fascinating development of frustrated Lewis pairs (FLPs). B(C6F5)(3)'s ability to catalytically activate Si-H bonds through eta(1) coordination opened the door to several unique reduction processes. The ground-breaking finding that the same family of fully or partially fluorinated boron Lewis acids allows for the related H-H bond activation, either alone or as a component of an FLP, brought considerable momentum into the area of transition-metal-free hydrogenation and, likewise, hydrosilylation. This review comprehensively summarises synthetic methods involving borane-catalysed Si-H and H-H bond activation. Systems corresponding to an FLP-type situation are not covered. Aside from the broad manifold of C=X bond reductions and C=X/C-X defunctionalisations, dehydrogenative (oxidative) Si-H couplings are also included.
Published in: Chemical Society reviews, 10.1039/c4cs00451e, Royal Society of Chemistry