New Paradigm in Ligand Coupling: Formation of C(sp2)–C(sp) Bonds by Hypervalent Bismuth
- 1Department of Chemistry
- 2University of Chicago
Abstract
Ligand coupling is the principal bond-forming reaction of hypervalent main-group compounds, resulting in the formation of diverse carbon–carbon and carbon–heteroatom bonds. Hypervalent organobismuth reagents are known to undergo ligand coupling to form C–O, C–N, C–S, and carbon–halogen bonds, together with carbon–carbon bonds between enolates and aryl groups or alkenes, and phenoxides and aryl groups. Despite four decades of development in organobismuth chemistry, however, coupling between aryl and alkynyl ligands has remained unreported. Here we show that hypervalent organobismuth undergoes aryl–alkynyl coupling through a previously unknown elementary ligand-coupling reaction. A conformationally constrained, recoverable organobismuth scaffold enables selective aryl transfer to terminal alkynes under mild, transition-metal-free conditions. Mechanistic studies support the intermediacy of a pentacoordinate Bi(V) species that is observable by variable-temperature NMR and capable of ligand exchange prior to reductive coupling. These studies establish aryl–alkynyl coupling as a new elementary reaction of hypervalent organobismuth compounds.
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BibTeX
@misc{shin2026paradigm,
title = {{New Paradigm in Ligand Coupling: Formation of C(sp2)–C(sp) Bonds by Hypervalent Bismuth}},
author = {Yun-Jeong Shin and Li Li and Viresh H. Rawal},
howpublished = {ChemRxiv},
year = {2026},
month = sep,
doi = {10.26434/chemrxiv.15008461/v1},
url = {https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008461/v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - New Paradigm in Ligand Coupling: Formation of C(sp2)–C(sp) Bonds by Hypervalent Bismuth
AU - Yun-Jeong Shin
AU - Li Li
AU - Viresh H. Rawal
PY - 2026
DA - 2026/09/07
PB - ChemRxiv
DO - 10.26434/chemrxiv.15008461/v1
UR - https://chemrxiv.org/doi/full/10.26434/chemrxiv.15008461/v1
AB - Ligand coupling is the principal bond-forming reaction of hypervalent main-group compounds, resulting in the formation of diverse carbon–carbon and carbon–heteroatom bonds. Hypervalent organobismuth reagents are known to undergo ligand coupling to form C–O, C–N, C–S, and carbon–halogen bonds, together with carbon–carbon bonds between enolates and aryl groups or alkenes, and phenoxides and aryl groups. Despite four decades of development in organobismuth chemistry, however, coupling between aryl and alkynyl ligands has remained unreported. Here we show that hypervalent organobismuth undergoes aryl–alkynyl coupling through a previously unknown elementary ligand-coupling reaction. A conformationally constrained, recoverable organobismuth scaffold enables selective aryl transfer to terminal alkynes under mild, transition-metal-free conditions. Mechanistic studies support the intermediacy of a pentacoordinate Bi(V) species that is observable by variable-temperature NMR and capable of ligand exchange prior to reductive coupling. These studies establish aryl–alkynyl coupling as a new elementary reaction of hypervalent organobismuth compounds.
ER -