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Title: Ionization of gold (γ-methoxy)vinyl complexes generates reactive gold vinyl carbene complexes
Cationic gold vinyl carbene/allylic cation complexes of the form ( E )-[(L)AuC(H)C(H)CAr 2 ] + OTf − {L = IPr, Ar = Ph [( E )- 5a ], L = IPr, Ar = 4-C 6 H 4 OMe [( E )- 5b ], L = P( t -Bu) 2 o -biphenyl, Ar = 4-C 6 H 4 OMe [( E )- 5c ]} were generated in solution via Lewis acid-mediated ionization of the corresponding gold (γ-methoxy)vinyl complexes ( E )-(L)AuC(H)C(H)C(OMe)Ar 2 at or below −95 °C. Complexes ( E )- 5b and ( E )- 5c were fully characterized in solution employing multinuclear NMR spectroscopy, which established the predominant contribution of the aurated allylic cation resonance structure and the significant distribution of positive charge into the γ-anisyl rings. Complex ( E )- 5b reacted rapidly at −95 °C with neutral two-electron, hydride, and oxygen atom donors exclusively at the C1 position of the vinyl carbene moiety and with p -methoxystyrene to form the corresponding vinylcyclopropane. In the absence of nucleophile ( E )- 5a decomposed predominantly via intermolecular carbene dimerization whereas formation of 1-aryl-5-methoxy indene upon ionization of ( Z )-(IPr)AuC(H)C(H)C(OMe)(4-C 6 H 4 OMe) 2 [( Z )- 6b ] implicated an intramolecular Friedel–Crafts or electrocyclic Nazarov pathway for the decomposition of the unobserved vinyl carbene complex ( Z )-[(IPr)AuC(H)C(H)C(4-C 6 H 4 OMe) 2 ] + OTf − [( Z )- 5b ].  more » « less
Award ID(s):
1800273
NSF-PAR ID:
10111499
Author(s) / Creator(s):
;
Date Published:
Journal Name:
Chemical Science
Volume:
10
Issue:
24
ISSN:
2041-6520
Page Range / eLocation ID:
6149 to 6156
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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  2. Abstract

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