The thionophosphate–thiolophosphate photoisomerization proceeds predominantly through a non-chain radical pathway. Synthetically viable benzylation of tetrahydrofuran, propan-2-ol and olefins

Abstract

The photoirradiation of thionophosphates, ROP(S)(OEt)₂, derived from benzyl and vinylogously benzyl alcohols in CH₃CN, with a Hanovia medium-pressure mercury lamp in a quartz vessel leads to the formation of the corresponding thiolophosphates, RSP(O)(OEt)₂, through a non-chain radical pathway. This behavior of thionophosphates is unlike that of the related phosphates, which react through ionic dissociation–recombination processes. When the irradiation is conducted in solvents such as PrⁱOH, THF and toluene, benzylation of these solvents takes place in synthetically respectable yields. Irradiation of thionophosphates in CH₃CN leads to a convenient allylic benzylation of olefins.