Opportune gem‐Silylborylation of Carbonyl Compounds: A Modular and Stereocontrolled Entry to Tetrasubstituted Olefins

Abstract

An easy access to highly versatile gem-silylboronate synthons is achieved by means of a new olefination reagent, HC(Bpin) (SiMe ). Subsequent silicon or boron-based selective functionalization allows for the modular and stereocontrolled synthesis of all-carbon tetrasubstituted alkenes. A particular attraction of this approach is the iododesilylation reaction, which becomes a pivotal tool for C-Si functionalization.

Unveiling the role of boroxines in metal-free carbon–carbon homologations using diazo compounds and boronic acids

“… 27 – 32 These doubly functionalised carbon substrates are of interest, as they may be used to generate sequential or orthogonal functionalization at the same carbon atom. 28 , 29 To date, the homologation with TMSCHN 2 has only been performed in combination with boronic acids to access the TMS-free homologation products. 26 , 33 While several proposed mechanisms have been reported, the role of a boronic acid anhydride (boroxine) intermediate in these reactions remains unclear.…”

Selective Boryl‐Anion Migration in a Vinyl sp2−sp3 Diborane Induced by Soft Borane Lewis Acids

“…For example, coordination of a carbanion containing a Br or OCb group (or a diazoalkane) to 1 led to loss of [OCb] − or [Br] − (or N 2 ) and the formation of 1,1‐diborylalkanes (Scheme 1 b) 11, 12, 13, 14, 15, 16, 17. We hypothesised that an alternative route to induce intramolecular 1,2‐boryl‐anion migration would be the activation of an unsaturated R − group (e.g.…”

Selective Boryl‐Anion Migration in a Vinyl sp2−sp3 Diborane Induced by Soft Borane Lewis Acids

“…[11][12][13][14][15][16][17] We hypothesised that an alternative route to induce intramolecular 1,2-boryl-anion migration would be the activation of an unsaturated R À group (e.g. [11][12][13][14][15][16][17] We hypothesised that an alternative route to induce intramolecular 1,2-boryl-anion migration would be the activation of an unsaturated R À group (e.g.…”