Sulfenylation and Selenenylation a to Carbonyl Groups

The a-sulfenylation138 and a-selenenylation139 of carbonyl compounds are synthetically important reactions, particularly in connection with the introduction of 

Electrophilic Additions to Carbon-Carbon Multiple Bonds 

II and 12 indicate, the selenenylation of ketones can also be effected by reactions of enol acetates or enol silyl ethers. 

---