title: PdI2-catalyzed coupling-cyclization reactions involving two different 2,3-allenols: an efficient synthesis of 4-(1',3'-dien-2'-yl)-2,5-dihydrofuran derivatives.
abstract: Transition-metal-catalyzed dimeric coupling-cyclization reactions of two different 2,3-allenols afforded 4-(1',3'-dien-2'-yl)-2,5-dihydrofuran derivatives 3. 2-Substituted 2,3-allenols 1 cyclized to form the 2,5-dihydrofuran ring, whereas the 2-unsubstituted 2,3-allenols 2 provided the 1,3-diene unit at the 4-position. The reaction is proposed to proceed through an oxypalladation, insertion, and beta-hydroxide elimination process. The C=C double bond was formed with high E stereoselectivity by beta-hydroxide elimination.
authors.affiliation: Laboratory of Molecular Recognition and Synthesis, Department of Chemistry, Zhejiang University, Hangzhou 310027, Zhejiang, PR China.
authors.forename: Youqian
authors.initials: Y
authors.lastname: Deng
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Shengming
authors.initials: S
authors.lastname: Ma