Recent Advances in Phosphine‐Promoted (4 + 1) Annulation Reactions

Abstract

Over the past two decades, the nucleophilic phosphine catalysis has effected many powerful annulation reactions and emerged as an intriguing platform for the generation of highly functionalized carbo‐ and heterocycles. In addition to the well‐established (3 + 2) annulation, the phosphine‐promoted (4 + 1) annulation has received increasing attention and developed rapidly in recent years, which complements the (3 + 2) annulation and also provides an alternative approach to structurally diverse five‐membered carbo‐ and heterocycles. This minireview summarizes the recent advances in phosphine‐promoted (4 + 1) annulation reactions according to the type of substrates used in the annulations.

Topics & Concepts