α‐Boryl Carbanions: The Influence of Geminal Heteroatoms in C−C Bond Formation

The wide applications of alpha‐boryl carbanions in selective coupling with organohalides, imines/carbonyls and conjugated unsaturated substrates has become an interesting tool for organic synthesis. Strategically, the inclusion of heteroatoms, such as Si, S, N, F, Cl, Br and I in the alpha position opens a new venue towards multifunctionalities in molecular design. Here, a conceptual and practical view on powerful carbanions, containing α‐silicoboron, α‐thioboron, α‐haloboron and α‐aminoboron is given, as well as a prespective on their efficient application for selective electrophilic trapping.