Abstract
Reactions of benzyl potassium species with CO are shown to proceed via transient carbene-like intermediates that can undergo either dimerization or further CO propagation. In a sterically unhindered case, formal dimerization of the carbene is the dominant reaction pathway, as evidenced by the isolation of ((Ph 3SiO)(PhCH 2)C) 2 2 and PhCH 2C(O)CH(OH)CH 2Ph 3. Reactions with increasingly sterically encumbered reagents show competitive reaction pathways involving intermolecular dimerization leading to species analogous to 2 and 3 and those containing newly-formed five-membered rings tBu 2C 6H 2(C(OSiR 3)C(OSiR 3)CH 2) (R=Me 6, Ph 7). Even further encumbered reagents proceed to either dimerize or react with additional CO to give a ketene-like intermediates, thus affording a 7-membered tropolone derivative 14 or the dione (3,5-tBu 2C 6H 3) 3C 6H 2CH 2C(O)) 2 15.
Original language | English |
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Pages (from-to) | 3640-3644 |
Journal | Chemistry – An Asian Journal |
Volume | 16 |
Issue number | 22 |
Early online date | 30 Sept 2021 |
DOIs | |
Publication status | E-pub ahead of print - 30 Sept 2021 |
Bibliographical note
Funding Information:D.W.S. is grateful to NSERC of Canada for research support and the award of a Canada Research Chair. The Guggenheim Foundation, the Killam Foundation and the RSC(UK) are thanked for a Guggenheim fellowship, a 2021 Killam Prize and a 2021 Centenary Prize, respectively. S.G and Z.W.Q are grateful to DFG (project SPP1807) for financial support. A.R.J. is grateful for a Banting Postdoctoral Fellowship for funding. M.X is grateful for the award of C.H. Bayley Scholarship. T.W. is grateful to China Scholarship Council for financial support. Dr. K. Demmans is thanked for collection of EPR spectra. Open Access funding enabled and organized by Projekt DEAL.
Keywords
- C−C bond formation
- carbene
- carbon monoxide
- radical
- tropolone
ASJC Scopus subject areas
- Biochemistry
- Organic Chemistry