Rhodium-Catalyzed Propargylic Substitution: A Divergent Approach to Propargylic and Allenyl Sulfonamides

摘要

The transition-metal-mediated substitution of propargylic alcohol derivatives using a stoichiometric cobalt–alkyne complex, represents a fundamentally important synthetic transformation that is often referred to as the Nicholas reaction.[1] The catalytic version of this process, in which a number of late-transition-metal complexes have been shown to be effective catalysts, has also been described.[2, 3] Nonetheless, a key and striking feature with many of the catalytic variants is the preponderance of aryl-substituted propargylic alcohols, which presumably circumvents the problem of bhydride elimination with alkyl derivatives.