Enantioselective Carbyne Transfer via Chiral Rh-Carbynoids

Abstract

his doctoral thesis focuses on the development of new catalytic transformations mediated by Rh(II)-carbynoid intermediates. Generated from hypervalent iodine diazo precursors, these reactive species enable unique carbon-transfer processes that expand the scope of modern synthetic methodology.

Chapter II describes a Rh(II)-catalyzed enantioselective single-carbon insertion into alkenes, proceeding through a chiral carbynoid intermediate to deliver allylic phosphates with high levels of stereo- and enantioselectivity. Chapter III presents a mechanistic investigation of this transformation, combining kinetic isotope effects, Hammett analysis, and stereochemical probes to support an unusual SN1-type SNi substitution pathway responsible of the enantiocontrol.

Chapter IV discloses a catalytic oxidative ligand transfer between Rh(II)-carbynoids and alkyl iodides, enabling selective formation of iodocyclopropanes with a variety of C–, O–, N and S–nucleophiles. We also show a new route to bicyclo[2.1.0]pentanes from the obtained iodocyclopropanes.