Diselenide- and Disulfide-Mediated Synthesis of Isocoumarins
作者:Sohail A. Shahzad、Claire Venin、Thomas Wirth
DOI:10.1002/ejoc.201000308
日期:——
Cyclizations of stilbenecarboxylic acids to the corresponding isocoumarin derivatives using diselenide or disulfide reagents have been developed. By employing bis(triflouroacetoxy)iodobenzene as oxidant for the 6-endo-trig cyclizations a variety of dihydroisocoumarins have been prepared in good yields. This method is capable of forming isocoumarins and dihydroisocoumarin derivatives by a cyclization–elimination
We developed a novel thiourea Lewis-base catalyst with phenol moieties for the enantioselective 5-exo-bromolactonization of stilbenecarboxylic acids to afford chiral 3-substituted phthalides. The phenol moieties are crucial for the enantio- and regio-selectivity.