Selected Diastereoselective Reactions:Diastereoselective Intra- and Intermolecular 1,3-Dipolr Cacloadditions in Natural Product Synthesis

Mulzer, Johann

Comprehensive Chirality 2012, 2, 525-562.

1,3-Dipolar cycloadditions have had an enormous impact in the area of heterocyclic synthesis. Intramolecular variations have proved particularly efficient to solve regio- and stereochemical problems and to increase the potential and efficiency of this reaction. The number of natural products or targeted molecules prepared by intramolecular 1,3-dipolar cycloadditions has increased tremendously over the past few years. In many cases the original heterocycle has been cleaved to generate acyclic structures, for instance amino alcohols in case of nitrone or nitrile oxide additions. In this report, the intramolecular addition of carbonyl ylides, nitrones, azomethine ylides and azomethine imines, nitrile oxides, and azides to olefins (and sometimes alkynes) is reviewed with particular emphasis on examples from 2000 onward. For the sake of comprehensiveness, some representative intermolecular cycloadditions from the recent literature are also included.