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Prying open a reactive site for allylic arylation by phosphine-ligated geminally diaurated aryl complexes

journal contribution
posted on 2023-05-18, 14:51 authored by Vikse, KL, Zavras, A, Thomas, TH, Alireza AriafardAlireza Ariafard, Khairallah, GN, Allan CantyAllan Canty, Brian YatesBrian Yates, O'Hair, RAJ
Gas-phase ion–molecule reaction experiments, theoretical kinetic modeling, and computational chemistry were used to examine the role of a second gold center in promoting allylic arylation. Geminally diaurated complexes [(L)nAu2Ph]+ are demonstrated to participate in C–C bond formation reactions with allyl halides, CH2═CHCH2X (X = Cl, Br, and I), given a favorable phosphine ligand architecture. Thus, while [(Ph3P)2Au2Ph]+, 1, is unreactive toward the allyl halides, [(dppm)Au2Ph]+, 2 (where dppm = bis(diphenylphosphino)methane, (Ph2P)2CH2), reacts via C–C bond coupling to produce [(dppm)Au2X]+. The reaction kinetics (efficiencies) follows the expected leaving group ability, X = I (58%) > Br (2%) > Cl (0.02%). DFT calculations were carried out to examine the potential mechanism for the C–C bond coupling reactions of 2 with each of the three allyl halides. The most favorable mechanism for C–C bond coupling of 2 requires the active participation of both gold centers in a redox couple mechanism wherein the allylic halide oxidatively adds across the gold centers to form a AuIAuIII complex with a weak Au···Au interaction, followed by intramolecular reductive elimination of allyl benzene from the AuIII center.

History

Publication title

Organometallics

Volume

34

Issue

13

Pagination

3255-3263

ISSN

0276-7333

Department/School

School of Natural Sciences

Publisher

Amer Chemical Soc

Place of publication

1155 16Th St, Nw, Washington, USA, Dc, 20036

Rights statement

Copyright 2015 American Chemical Society

Repository Status

  • Restricted

Socio-economic Objectives

Expanding knowledge in the chemical sciences

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