P(NMe2)3-Mediated Reductive Intramolecular Annulation of Benzoylformates Tethered with a Trisubstituted Alkene Unit and Synthesis of 2,2-Disubstituted 2 H-Chromenes

Jiayong Zhang; Yuhe Qiu; Biao Zhang; Zhiqiang Huang; Zhengjie He

doi:10.1021/acs.orglett.1c00286

P(NMe₂)₃-Mediated Reductive Intramolecular Annulation of Benzoylformates Tethered with a Trisubstituted Alkene Unit and Synthesis of 2,2-Disubstituted 2 H-Chromenes

Org Lett. 2021 Mar 5;23(5):1880-1885. doi: 10.1021/acs.orglett.1c00286. Epub 2021 Feb 17.

Authors

Jiayong Zhang¹, Yuhe Qiu¹, Biao Zhang¹, Zhiqiang Huang¹, Zhengjie He^{1

2}

Affiliations

¹ The State Key Laboratory of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China.
² Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300071, China.

PMID: 33595333
DOI: 10.1021/acs.orglett.1c00286

Abstract

In this report, a P(NMe₂)₃-mediated reductive intramolecular annulation reaction has been developed with benzoyl formates bearing a trisubstituted alkene unit. It provides a facile synthesis of highly functionalized 2,2-disubstituted 2H-chromenes with a broad substrate scope and high efficiency. Experimental results suggest this annulation reaction proceeds via a cascade of alkene isomerization/vinyl o-quinone methide formation/6π-electrocyclization. As a key intermediate, the vinyl-substituted o-quinone methide is presumably generated by a Kukhtin-Ramirez adduct initiated O → C vinyl migration.

Publication types

Research Support, Non-U.S. Gov't