Syntheses of Tungsten Complexes with Various (1 ,3-Dithioliumyl) Diphenylphosphine Containing Ligands

Abstract

The (dithioalkylcarbonyl)diphenylphosphino tungsten complexes W(CO)_5[PPh_2(CS_2R)](2-4)(R=CH_2C≡CH; CH_2C≡N; CH(CH_3)C≡N) are accessible by the alkylation reactions of complex [Et_4N][W(CO)_5PPh_2CS_2] (1) with unsaturated organic halides. Protonation of 2-4 with HBF_4 at room temperature cause intramolecular cyclization to form the cationic complexes The equation is abbreviated (8) is produced by the react ion of J or 6 with Ph_3CBF_4. In complexes 5-7, prolon-induced intramolecular cyclizations followed by unprecedented 1.3．hydrogen shift formation of five-membered cationic 1,3-dithiolium rings were confirmed by the reaction of 3 and Ph_3CBF_4. Protonation of 2 to form 5 is not reversible, but deprotonation of 6 by n-BuLi or PPh_3 gives 3 quantitatively. Treatment of 6 with n-Bu_4NF yields complex W(CO)_5,PPh_2F and 3 with a 1:1 ratio, but in the reaction of 5 with n-Bu_4NF only compound W(CO)_5PPh_2F is formed.