Efficient and stereodivergent synthesis of unsaturated acyclic fragments bearing contiguous stereogenic elements.

Abstract

Synthetic organic strategies that enable the catalytic and rapid assembly of a large array of organic compounds possessing multiple stereocenters in acyclic systems are somewhat rare, especially when it comes to reaching today’s high standards of efficiency and selectivity. In particular, the catalytic preparation of a three-dimensional molecular layout of a simple acyclic hydrocarbon skeleton possessing several stereocenters from simple and readily available reagents still represents a vastly uncharted domain. Here, we report a rapid, modular, stereodivergent and diversity-oriented unified strategy to construct acyclic molecular frameworks bearing up to four contiguous and congested stereogenic elements, with remarkably high levels of stereocontrol and in only three catalytic steps from commercially available alkynes. A regio- and diastereoselective catalytic Heck migratory insertion reaction of alkenylcyclopropyl carbinols merging selective C–C bond cleavage of a cyclopropane represents the key step.