A [4+2] annulation of aldehydes and o-quinone methides catalyzed by a secondary amine is developed. This process leads to biologically important dihydrocoumarins in moderate to good yields after oxidation. In addition, the employment of a chiral secondary amine catalyst allows access to optically active dihydrocoumarins with up to 64% ee.
Synthesis of Chiral 3-Alkyl-3,4-dihydroisocoumarins by Dynamic Kinetic Resolutions Catalyzed by a Baeyer−Villiger Monooxygenase
作者:Ana Rioz-Martínez、Gonzalo de Gonzalo、Daniel E. Torres Pazmiño、Marco W. Fraaije、Vicente Gotor
DOI:10.1021/jo902519j
日期:2010.3.19
Baeyer−Villigermonooxygenases have been tested in the oxidation of racemic benzofused ketones. When employing a single mutant of phenylacetone monooxygenase (M446G PAMO) under the proper reaction conditions, it was possible to achieve 3-substituted 3,4-dihydroisocoumarins with high yields and optical purities through regioselective dynamic kinetic resolution processes.