Direct dehydroxy(sulfhydryl)xanthylation of alcohols and thiols

Abstract

Alkyl xanthates are broadly applied as synthetic intermediates for expedient access to a range of functional group derivatives in synthetic chemistry. Dehydroxyxanthylations of naturally rich alcohols are a promising approach but have rarely been explored mainly due to their challenging activation mode. Herein, we report the direct dehydroxyxanthylation of a wide range of primary and secondary alcohols via easily accessible and shelf-stable electrophilic N-xanthyl phthalimides under mild conditions, with superb functional group compatibility toward cyano and nitro groups, unprotected active groups (–NH₂ and –OH), and double and triple bonds. The present organic halide-free protocol might provide a new and green avenue toward the synthesis of alkyl xanthates in an umpolung Mitsunobu-type manner in organic synthesis. Additionally, aliphatic thiols successfully undergo desulfhydrylxanthylation to produce the corresponding sp³C-xanthates. Notably, the xanthamide and thioxanthate groups could also be transformed to the desired alkyl substrates via this umpolung strategy. The broad substrate scope, excellent functional group compatibility and late-stage functionalization of bioactive molecules makes this protocol very attractive as a novel strategy for the rapid incorporation of SC(S)R (R = OEt, Oalkyl, NEt₂ and SEt) onto the alkyl chains of complex systems.