Diethyl aryl phosphates, synthesis

A new cyclising reagent is proposed for the synthesis of 5-unsubstituted 1,3,4-thiadiazoles (133). The latter are formed in good yield by the reaction of thiohydrazides (134) with diethyl chlorophosphate (Scheme 39). A useful, one-pot protocol has been developed for the conversion of enolizable ketones (135) to alkylated or arylated olefins (136) by Pd-catalysed cross coupling of in-situ generated enol phosphates (137) with Grignard reagents (Scheme 40). ... 

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