Tuning Selectivity In The Reaction Of Arylboronic Acids With α,β-Unsaturated Carbonyl Compounds Catalyzed By Rhodium: Heck-type Coupling Versus Conjugate Addition

This thesis deals with tuning the selectivity of Heck-type coupling vs conjugate addition (HC/CA) in rhodium-catalyzed reactions of arylboronic acids with a, β-unsaturated carbonyl compounds in toluene-H₂O, consisting of four parts:1. Tuning HC/CA selectivity in the reaction of arylboronic acids with α,β-unsaturated esters catalyzed by rhodium. The influence of the reaction conditions and phosphine ligands on the selectivity of rhodium-catalyzed Heck-type coupling and conjugate addition (HC/CA) between phenylboronic acid and butyl acrylate was systematically investigated. The optimized conditions for Heck-type coupling and conjugate addition were obtained ( HC: 3mol%RhCl₃-12mol%PPh₃\ 3eq.K₂CO₃\ excess olefin; CA: 3mol%RhCl₃-15mol%BINAP\ no base\ excess boronic acid). Under the optimized conditions, the reactions of arylboronic acids with butyl acrylate and phenylboronic acid with α,β-unsaturated esters were investigated respectively with the conclusion that the reaction of arylboronic acids with α,β-unsaturated esters can be tuned to favor Heck-type coupling (selectivity up to 100%) or conjugate addition ( selectivity up to 99%).2. Tuning HC/CA selectivity in the reaction of arylboronic acids with α,β-unsaturated amides catalyzed by rhodium. Similar to the reaction of arylboronic acids with α,β-unsaturated esters, by using the reaction of phenylboronic acid with N, N-dimethyl acrylamide as the model, the optimized conditions for Heck-type coupling(HC) and conjugate addition(CA) reactions of arylboronic acids with α,β-unsaturated amides were obtained through systematic investigation of reaction conditions ( HC: 3mol%RhCl₃-12mol%PPh₃\3eq.K₂CO₃\excess olefin; CA: 3mol%RhCl₃ -10mol%dppp\ no base\ excess boronic acid). Then under these optimized conditions, the reactions of arylboronic acids with N,N-dimethyl acrylamide and phenylboronic acid with α,β-unsaturated amides were investigated respectively leading to successful tuning the reaction of arylboronic acids with α,β-unsaturated amides to favor Heck-type coupling (selectivity up to 99%) or conjugate addition ( selectivity up to 100%).3. Tuning HC/CA selectivity in the reaction of arylboronic acids with α,β-unsaturated ketones catalyzed by rhodium. Similar to the reactions of α,β-unsaturated amides and esters, through systematically investigating the selectivity...