Synthesis of O‐ and N‐Heterocycles by Silyl‐Prins Cyclization of Allylsilanes
Prins cyclization has emerged as one of the most valuable methods for the construction of heterocycles. It proceeds through intramolecular addition of a π-nucleophile to an oxocarbenium or related ion. The use of electron-rich alkenes, such as allylsilanes (so-called silyl-Prins cyclization) offers the benefit of allowing more selective reactions. The regio- and stereochemical outcomes of these transformations are explained by well-stablished transition states. This review presents the most important contributions involving silyl-Prins cyclization to the stereoselective preparation of oxygen and nitrogen heterocycles. The influence of different structural variants in the selectivity of the cyclization is discussed. These reactions have frequently been used as key steps in the synthesis of a wide variety of natural products.