Stereoselective Synthesis of Aryl Cyclopentene Scaffolds by Heck-Matsuda Desymmetrization of 3-Cyclopentenol
作者:Ricardo A. Angnes、Juliana M. Oliveira、Caio C. Oliveira、Nelson C. Martins、Carlos Roque D. Correia
DOI:10.1002/chem.201404159
日期:2014.10.6
enantioselective Heck–Matsudadesymmetrization reaction was accomplished by using 3‐cyclopentenol to produce chiral five‐membered 4‐aryl cyclopentenol scaffolds in good yields and high ee’s, together with some 3‐aryl‐cyclopentanones as minor products. Mechanistically, the hydroxyl group of 3‐cyclopentenol acts as a directing group and is responsible for the cis‐ arrangement in the formation of the 4‐aryl‐cyclopentenols
For the first time the room-temperature rhodium-catalyzedasymmetric1,4-addition of potassium aryltrifluoroborates to α,β-unsaturated substrates is described. Thanks to the use of a chiral diene as ligand for rhodium and triethylamine as base, to facilitate transmetalation of the boron species, high yields and enantioselectivities were generally achieved. Moreover, the use of such tetravalent boron