Dienes hydroesterification

The hydroesterification of dienes gave both the unsaturated monoesters and saturated diesters.524 In some cases, y-ketoesters were obtained and carbonylation of 1,5-cyclooctadiene in absence of alcohol gave a ketone.525 [PdI2(PBu3)2] was used as catalyst. If the catalyst contained a halide anion, butadiene underwent normal hydroesterification. When halide-free catalysts were used, the reaction took a different course. Dimerization of the diene occurred to give the ester of 3,8-nonadienoic acid as the major product (equation 128).526-528... 

Many other addition reactions of olefins, dienes, and acetylenes are known, which are catalyzed by metal carbonyls including Ni(CO)4, Fe(CO)5, and Co2(CO)8 and by carbonyl derivatives such as hydrocarbonyls or phosphine-substituted carbonyls. Among these are the hydro-carboxylation, hydroesterification, and hydrocyanation of olefins the synthesis of hydroquiniones from acetylenes, carbon monoxide, and water ... 

The hydroesterification of dienes gave both the unsaturated monoesters and saturated diesters. 

The hydroesterification of butadiene is not well developed, although much effort in many industrial laboratories has been spent to develop this process as a method to prepare adipic add and caprolactam. Because little information on this process has been disclosed in 1he academic literature, this topic is not presented in detail here. Challenges encountered in developing this reaction include the regioselectivity for formation of terminal esters, the potential to form stable allyhnetal intermediates, and the potential to form polymeric or oligomeric products containing multiple diene units. 

---