Les trifluoro(organo)borates de potassium : nouvelles perspectives pour la formation de liaisons carbone-carbone à l'aide de complexes du rhodium

Overview & Synopsis

This manuscript describes the use of potassium trifluoro(organo)borates in rhodiumcatalyzed carbon-carbon bond forming reactions. These easy to purify and very stable reagents turned out to constitute a valuable alternative to other boron reagents commonly used in transition metal catalyzed reactions. Asymmetric rhodium-catalyzed 1,4-additions of trifluoroborates were developed with the use of a chiral diphosphine which allowed a good control of the enantioselectivity. Under neutral conditions Michael adducts were obtained from various acceptors in nearly quantitative yield avoiding the use of a large excess of organometallic reagent. A new catalytic method for 1,2-addition allowed an easy and straightforward access to various alcohols. This general reaction proceeds under very mild conditions and was applied to the synthesis of substituted carbinols. Finally, a new cross-coupling reaction between organometallic reagents (boron and tin derivatives) and aldehydes has been discovered. This C-H bond activation has allowed an easy access to dissymmetric ketones using nonfunctionalized derivatives.