Synergistic Pd(0)/Rh(II) Dual Catalytic [6 + 3] Dipolar Cycloaddition for the Synthesis of Monocyclic Nine-Membered N,O-Heterocycles and Their Alder-ene Rearrangement to Fused Bicyclic Compounds
- 등재 SCIE, SCOPUS
- 발행기관 American Chemical Society
- 발행년도 2021
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000181907
- 본문언어 영어
- Published As http://dx.doi.org/10.1021/acs.orglett.1c01135
초록/요약
The catalytic construction of a monocyclic medium-sized N,O-heterocyclic ring represents a formidable challenge in organic synthesis. Herein we report the synergistic palladium(0)/rhodium(II) dual catalytic cycloaddition of vinylpropylene carbonates with N-sulfonyl-1,2,3-triazoles to afford monocyclic nine-membered N,O-heterocycles. The catalytically generated 1,6-dipole-equivalent zwitterionic π-allyl palladium(II) complex and the 1,3-dipole-equivalent α-imino rhodium(II) carbenoid intermediate react with each other in a formal [6 + 3] dipolar cycloaddition to furnish nine-membered oxazonines, which can be transformed into cis-fused [4.3.0] bicyclic compounds via a transannular Alder-ene rearrangement. The tandem one-pot cycloaddition/Alder-ene rearrangement sequence is also possible. © 2021 American Chemical Society.
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