Study of dirhodium(II)-catalyzed hetero-Diels-Alder reactions: Investigations of diene influence and substitution pattern.

Abstract

Studies pertaining to the dirhodium(II) carboxamidate catalyzed hetero-Diels-Alder reaction between 1-methoxy-2-methyl-3-(trimethylsilyloxy)-1,3-butadiene and various aldehydes have been carried out. It has been demonstrated that the overall yield, enantioselectivity, and rate of reaction for the hetero-Diels-Alder process are influenced by the substitution pattern of the diene. Collected data has allowed for the evaluation of the structural and electronic properties of the catalysts and for comparisons to be made between several dienes of interest. The complete synthesis of Rh₂(4R-dFIBAZ)₄, a dirhodium(II) carboxamidate catalyst that has shown increased reactivity for diazo decomposition and enhanced selectivity for ylide formation, has been previously reported by our group. Presented herein are the attempts taken to improve the existing synthesis through optimization and scale-up.