TRANSMISSION OF CHIRALITY FROM SULFUR TO CARBON

The sulfinyl group is characterized by the presence of ligands very different from each other from the stereoelectronic point of view: the lone-pair, the oxygen and two aryl or alkyl groups. This accounts for the generally high stereoselectivity met with in reactions involving chiral or prochiral groups α or β to the sulfur moiety. Transmission of chirality from sulfur to carbon has been observed i) in the α-hologenation of sulfoxides, ii) in the addition of nucleophiles and electrophiles to α, β unsaturated sulfoxides, iii) in the formation of allenic sulfoxides, and iv) in the reduction of alkylidensulfinamides and of β-ketosulfoxides. The high degree of asymmetric induction allows in most cases to rationalize the absolute configuration of the reaction products in terms of mechanism and steric factors.