Reactivity of a Nickel Acylate Complex with Acetylenes under an Ar and a CO Atmosphere

Abstract

The reaction of an alkyl nickel acylate complex with a variety of mono-and disubstituted acetylene derivatives was investigated. Depending upon the substitution pattern and the reaction time, the reaction product can be a 1,4-diketone, a cyclopentenone, or a γ-lactone, but only when the reaction is performed under an Ar atmosphere. When a CO atmosphere is used, no reaction occurs. The mechanism for formation of each of these compounds is discussed.OM9906767

Palladium‐catalyzed carbonylative cyclization of 3‐bromoallyl alcohols leading to furan‐2(5H)‐ones

“…Removal of the solvent left a crude mixture, which was separated by column chromatography (hexane/ethyl acetate = 10/1) to give furan‐3(5 H )‐ones. Except for known 4a , 4b , 4g , 4h and 4i , all new products prepared by the above procedure were characterized spectroscopically as shown below.…”