ABSTRACT
A process which offers the opportunity to reduce the waste and eliminate the use of hazardous solvents is the carbonylation of the commercially available αchloropinacolone (1) (1-chloro-3,3-dimethyl-2-butanone). (See Reaction [1].) Unfortunately, earlier experience with the (Ph3P)3PdCl2 catalyzed carbonylation of α-bromopinacolone was not encouraging. (17) Consistent with the previously reported carbonylation of α-bromoacetophenone (18), the carbonylation of αbromopinacolone gave low yields (64%) while demonstrating limited turnover numbers (<100). However, recent reports on the carbonylation of chloroacetone and α-chloroacetophenones using (Ph3P)PdCl2 (19, 20) noted significant yield improvements over the bromo analogs and prompted us to re-examine the alternative carbonylation process.
