Efficient synthesis of β-substituted α-haloenones by rhodium(II) catalyzed and thermal reactions of iodonium ylides

Rhodium(II)-catalyzed and thermal reaction of iodonium ylides are described. Rhodium(II)-catalyzed reactions of iodonium ylides with benzyl halides and acid halides afforded alpha-chloro-alpha,beta-enones and alpha-bromo-alpha,beta-enones in good yields, whereas thermal reactions of iodonium ylides in a solvent such as benzene afforded alpha-iodo-alpha,beta-enones in good yields.