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Stereo- and Regioselective Alkyne Hydrometallation with Gold(III) Hydrides.

ABSTRACT: The hydroauration of internal and terminal alkynes by gold(III) hydride complexes [(C^N^C)AuH] was found to be mediated by radicals and proceeds by an unexpected binuclear outer-sphere mechanism to cleanly form trans-insertion products. Radical precursors such as azobisisobutyronitrile lead to a drastic rate enhancement. DFT calculations support the proposed radical mechanism, with very low activation barriers, and rule out mononuclear mechanistic alternatives. These alkyne hydroaurations are highly regio- and stereospecific for the formation of Z-vinyl isomers, with Z/E ratios of >99:1 in most cases.

SUBMITTER: Pintus A

PROVIDER: S-EPMC5113781 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature

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Stereo- and Regioselective Alkyne Hydrometallation with Gold(III) Hydrides.

Pintus Anna A Rocchigiani Luca L Fernandez-Cestau Julio J Budzelaar Peter H M PH Bochmann Manfred M

Angewandte Chemie (International ed. in English) 20160904 40

The hydroauration of internal and terminal alkynes by gold(III) hydride complexes [(C^N^C)AuH] was found to be mediated by radicals and proceeds by an unexpected binuclear outer-sphere mechanism to cleanly form trans-insertion products. Radical precursors such as azobisisobutyronitrile lead to a drastic rate enhancement. DFT calculations support the proposed radical mechanism, with very low activation barriers, and rule out mononuclear mechanistic alternatives. These alkyne hydroaurations are hi ...[more]

PMID: 27592697

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