Generation of dialkyl phosphonodithioyl radicals and their addition onto alkenes. Synthesis of 3-phosphonodithiomethyl-3-deoxofuranosides
作者:Chrystel Lopin、Arnaud Gautier、Géraldine Gouhier、Serge R Piettre
DOI:10.1016/s0040-4039(00)01830-x
日期:2000.12
An efficient. three-step preparation of the new 2-phenylselanyl-[1,2,3]-dithiaphosphinane-2-oxide (8) from PCI, is described. The reagent is shown to behave as a precursor of the corresponding phosphonodithioyl radical, when placed in the presence of tin or silyl radicals. A novel synthesis of S,S-dialkyl phosphonodithioates is described based on these results. Application of this methodology to exocyclic 3-methylene-3-deoxofuranosides leads to the highly diastereoselective formation of 3-phosphonodithiomethyl-3-deoxofuranosides. (C) 2000 Elsevier Science Ltd. All rights reserved.
Phosphonyl, Phosphonothioyl, Phosphonodithioyl, and Phosphonotrithioyl Radicals: Generation and Study of Their Addition onto Alkenes
作者:Chrystel Lopin、Géraldine Gouhier、Arnaud Gautier、Serge R. Piettre
DOI:10.1021/jo0348064
日期:2003.12.1
The treatment of benzyl dialkylphosphites and dithiophosphites with benzeneselanyl chloride generates an Arbuzov-type transformation leading to the dialkyl selenophosphates 19a and 19b and to selenophosphorodithioates 21a and 21b. Interaction of these substrates with Lawesson's reagent yields the corresponding selenophosphorothioates 20a and 20b and the selenophosphorotrithioates 22a and 22b. When