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Sulfones as Synthetic Linchpins: Transition‐Metal‐Free sp 3 –sp 2 and sp 2 –sp 2 Cross‐Couplings Between Geminal Bis(sulfones) and Organolithium Compounds
Author(s) -
Trost Barry M.,
Kalnmals Christopher A.
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201800118
Subject(s) - umpolung , electrophile , nucleophile , synthon , chemistry , geminal , medicinal chemistry , carbanion , stereochemistry , organic chemistry , catalysis
A valuable umpolung strategy that highlights the ambiphilic nature of the bis(phenylsulfonyl)methyl synthon and demonstrates its utility as a synthetic linchpin is reported. Although the bis(phenylsulfonyl)methyl group is typically introduced as an sp 3 ‐carbon nucleophile, it is demonstrated that it can also function as an effective sp 2 ‐carbon electrophile in the presence of organolithium nucleophiles. Alkyl‐ and aryllithiums couple with the central carbon of the bis(phenylsulfonyl)methyl unit to ultimately generate trisubstituted alkenes, comprising formal sp 3 –sp 2 and sp 2 –sp 2 cross‐couplings between organolithium reagents and bis(sulfones). This process occurs almost instantaneously at −78 °C in the absence of any transition metals. By developing this curious transformation, it has been demonstrated that bis(phenylsulfonyl)methane is a valuable synthetic linchpin, which can undergo two C−C bond‐forming processes as an sp 3 ‐nucleophile, followed by a third C−C bond‐forming reaction as an effective sp 2 ‐electrophile. This discovery significantly enhances the utility of this ubiquitous, but underutilized, linker group.