LI2S2 AND LISR SPECIES BY LITHIUM TRIETHYLBOROHYDRIDE REDUCTION OF ELEMENTAL SULFUR AND DISULFIDES NEW METHODOLOGY FOR THE INTRODUCTION OF SULFUR INTO ORGANIC-MOLECULES - SYNTHESIS OF ANHYDROUS LI2S

Anhydrous THF solutions of Li 2 S or Li 2 S 2 (or chemically equivalent species) are rapidly and quantitatively formed by the reaction of common yellow sulfur with appropriate stoichiometries of commercially available LiEt 3 BH. Only volatile by-products H 2 and Et 3 B are produced; however, the Et 3 B probably associates with the anionic sulfur species generated. Subsequent reaction with electrophiles (alkylating agents or acylating agents) affords sulfide or disulfide derivatives in high yields. In several cases, literature procedures are substantially improved. Disulfides are cleaved to lithium mercaptides by LiEt 3 BH. Subsequent addition of electrophiles affords unsymmetrical sulfides. Trisulfides and tetrasulfides can also be prepared by LiEt 3 BH reduction of S g , but only in low yield. 1979.

NEW METHODOLOGY FOR THE INTRODUCTION OF SULFUR INTO ORGANIC-MOLECULES - SYNTHESIS OF ANHYDROUS LI2S, LI2S2 AND LISR SPECIES BY LITHIUM TRIETHYLBOROHYDRIDE REDUCTION OF ELEMENTAL SULFUR AND DISULFIDES Academic Article