Study On Oxidative Carbonylation Of Aromatic Boronic Acid Catalyzed By Palladium

Carbonylation reaction is a convenient way to introduce carbonyl groups into organic compounds. It is widely used in preparation of aldehydes, ketones, amides and esters. Heck and co-workers first reported the palladium-catalyzed carbonylation reactions of aryl chlorides to prepare aromatic aldehydes in1974. Since then, great effort has been devoted to develop carbonylation reactions. Progress has been made in palladium catalysed carbonylation reactions of aryl compounds in recent years, thanks to the advancement of organometallic chemistry. The first part of the thesis gives a brief review of carbonylation and oxidative carbonylation reactions, with an emphasize on carbonylation of arylboronic acids.Chapter2of the thesis describes a Pd-catalyzed oxidative carbonylation of arylboronic acids for the synthesis of symmetrical diarylketones. A series of symmetric benzophenones were obtained with Pd(OAc)2and phosphorus ligand as catalyst at low temperature (40℃) and low CO pressure (1atm). This method provides a simple and feasible way to synthesise symmetric benzophenones.Chapter3the thesis presents a Pd-catalyzed carbonylation for the construction of tertiary and quaternary carbon center by using carbon nucleophiles. Inspired by the work in Chapter2, carbon nucleophiles were used to trap the possible acyl palladium intermediate, aiming for the discovery of new carbonylation reactions. Diethyl malonates and acetylacetones were found to be viable nucleophiles for carbonylation of boronic acids, with Pd(TFA)2/BINAP as catalyst,t-BuOLi as base, at5bar of CO pressure,80℃. Under this reaction conditions, various tri-carbonyl compounds were prepared with high yields. Preliminary mechanistic was carried out to probe the mechanism of this new carbonylation reaction.