◊ These authors contributed equally to this work.
Abstract
N-Heterocyclic carbene catalysis allows the rapid formation of functionalized carbon–carbon
bonds. Our group has spent the previous decade focusing on broadening practical applications
of this type of catalysis. The design and discovery of novel reactivities and catalysts
in our group can best be divided into work focusing on the Stetter, ring-expansion,
and cross-benzoin reactions. Along with our expansion of the reaction scope, our introduction
of novel bis(amino)cyclopropenylidene catalysts for the Stetter reaction successfully
suppresses formation of side products, increasing synthetic utility. Concurrent work
on ring-expansion reactions allows access to functionalized lactones and lactams.
In addition to expanding the scope of the cross-benzoin reaction through use of α-ketoesters
and α-amino aldehydes, the introduction of a new triazolylidene catalyst has allowed
access to general chemoselective cross-benzoin reactions between aliphatic and aromatic
aldehydes.
1 Introduction
2 Stetter Reactions
2.1 Domino Stetter Reactions
3 Ring-Expansion Reactions
4 Cross-Benzoin Reactions
5 Summary and Outlook
Key words
N-heterocyclic carbenes - organocatalysis - Stetter reaction - benzoin - enantioselective
catalysis - ring expansion - cross-benzoin reaction
