Synthesis and Photochemistry of a New Photolabile Protecting Group for Propargylic Alcohols

Abstract

A new and efficient thiochromenone S,S-dioxide-based photolabile protecting group for propargylic alcohols is described. Robust protection reactions were developed through copper (II)-catalyzed substitution of propargylic alcohols. Subsequent photodeprotection proceeded smoothly to give the corresponding propargylic alcohols quantitatively within 15 minutes, as demonstrated by ¹H NMR spectroscopy and HPLC. Notably, the photoproduct derived from the thiochromenone derivatives showed a high fluorescence quantum yield, permitting monitoring of the reaction progress by fluorescence spectroscopy. A new strategy for the synthesis of triazoles by a one-pot reaction is also presented.

Key words

thiochromenone dioxides - protecting group - propargylic alcohols - photodeprotection - photolabile groups - triazoles

• References and Notes

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