Dedicated to Professor Friedrich Hammerschmidt on the occasion of his retirement
Abstract
α-Functionalized organolithium reagents (e.g., LiCH2X) are versatile reagents for accomplishing homologations of carbon- and heteroatom-type
electrophiles. The proper selection of the reaction conditions allows one to direct
their intrinsic ambiphilicity towards the nucleophilic character. Herein, the homologation
of various electrophiles ranging from Weinreb amides to isocyanates, carbonyl derivatives,
and chalcogenides – with a particular focus on the chemoselectivity of the processes
– is summarized.
1 Introduction
2 Homologation of Weinreb Amides
3 Homologation of Cyclic Ketones
4 Homologation of Isocyanates
5 Homologation of Disulfides and Diselenides
6 Conclusions
Key words
carbenoids - lithium - homologation - chemoselectivity - organometallic reagents