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Origins of stereoselectivity in the oxido-alkylidenation of alkynes.

ABSTRACT: A mild, convenient oxido-alkylidenation of alkynes is described. The three-step sequence involves the 1,3-dipolar cycloaddition of a nitrone and an alkynoate, oxidation of the resulting isoxazoline, and stereoselective extrusion of nitrosomethane. Quantum mechanical calculations identified the interactions of R3 with the oxidant and the preferred conformation of a diradical intermediate as major factors controlling the stereoselectivity of the oxidation and torquoselectivity of the extrusion.

SUBMITTER: Canterbury DP

PROVIDER: S-EPMC2662994 | biostudies-literature | 2008 Oct

REPOSITORIES: biostudies-literature

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Origins of stereoselectivity in the oxido-alkylidenation of alkynes.

Canterbury Daniel P DP Frontier Alison J AJ Um Joann M JM Cheong Paul H-Y PH Goldfeld Dahlia A DA Huhn Richard A RA Houk K N KN

Organic letters 20080918 20

A mild, convenient oxido-alkylidenation of alkynes is described. The three-step sequence involves the 1,3-dipolar cycloaddition of a nitrone and an alkynoate, oxidation of the resulting isoxazoline, and stereoselective extrusion of nitrosomethane. Quantum mechanical calculations identified the interactions of R3 with the oxidant and the preferred conformation of a diradical intermediate as major factors controlling the stereoselectivity of the oxidation and torquoselectivity of the extrusion. ...[more]

PMID: 18798638

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