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Updated: Dec 9, 2025

Light-driven Enzymatic Decarboxylation
Published on: May 22, 2016
Transition-Metal-Free and Visible-Light-Mediated Desulfonylation and Dehalogenation Reactions: Hantzsch Ester Anion
Micaela D Heredia1, Walter D Guerra1, Silvia M Barolo1
1INFIQC, Facultad de Ciencias Quı́micas, Universidad Nacional de Córdoba, X5000HUA Córdoba, Argentina.
Abstract:
Novel approaches for N- and O-desulfonylation under room temperature (rt) and transition-metal-free conditions have been developed. The first methodology involves the transformation of a variety of N-sulfonyl heterocycles and phenyl benzenesulfonates to the corresponding desulfonylated products in good to excellent yields using only KOBu in dimethyl sulfoxide (DMSO) at rt. Alternately, a visible light method has been used for deprotection of N-methyl-N-arylsulfonamides with Hantzsch ester (HE) anion serving as the visible-light-absorbing reagent and electron and hydrogen atom donor to promote the desulfonylation reaction. The HE anion can be easily prepared in situ by reaction of the corresponding HE with KOBu in DMSO at rt. Both protocols were further explored in terms of synthetic scope as well as mechanistic aspects to rationalize key features of desulfonylation processes. Furthermore, the HE anion induces reductive dehalogenation reaction of aryl halides under visible light irradiation.
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