Phosphine-catalyzed [3 + 2] and [4 + 2] annulation reactions of ynones with barbiturate-derived alkenes. Issue 25 (9th June 2017)

• Record Type: Journal Article
• Authors: Gao, Xing; Li, Zhen; Yang, Wenjun; Liu, Yang; Chen, Wufeng; Zhang, Cheng; Zheng, Lufei; Guo, Hongchao
• Is Part Of: Organic & biomolecular chemistry. Volume 15:Issue 25(2017)
• Page Start: 5298
• Page End: 5307
• Publication Date: 2017-06-09
• Subjects: Chemistry, Organic -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1039/c7ob01034f
• Languages: English
• ISSNs: 1477-0520

Abstract

Abstract : The phosphine-catalyzed [3 + 2] annulation reaction of ynones and barbiturate-derived alkenes has been developed with the assistance of a weak acid, giving functionalized spirobarbiturate-cyclopentanones. Abstract : The phosphine-catalyzed [3 + 2] annulation reaction of ynones and barbiturate-derived alkenes has been developed with the assistance of a weak acid, giving functionalized spirobarbiturate-cyclopentanones in moderate to excellent yields with excellent E / Z stereoselectivity. An unprecedented [4 + 2] annulation of ynones with barbiturate-derived alkenes was also achieved in the presence of a phosphine catalyst and an inorganic base, affording biologically interesting 1, 5-dihydro-2 H -pyrano[2, 3- d ]pyrimidine-2, 4(3 H )-dione derivatives. An asymmetric variant of the [3 + 2] annulation reaction has been explored and a moderate enantioselectivity was obtained when a bifunctional chiral phosphine was used as a chiral catalyst. A plausible mechanism was proposed to illuminate two different reaction pathways.