Phosphine-Catalyzed [4 + 2] Annulation: Synthesis of Cyclohexenes
作者:Yang S. Tran、Ohyun Kwon
DOI:10.1021/ja0752181
日期:2007.10.1
Phosphine-catalyzed [4 + 2] annulations of α-alkylallenoates with activated olefins allow the efficient syntheses of cyclohexenes. Hexamethylphosphorous triamide (HMPT)-catalyzed [4 + 2] annulations of α-alkylallenoates with arylidenemalononitriles provided highly functionalized 5,5-dicyano-4,6-disubstituted cyclohex-1-enecarboxylates in excellent yields (77−98%) and moderate to high diastereoselectivities