Rhodium-Catalyzed Synthesis of Organosulfur Compounds using Sulfur

Sulfur is one of the few elements that occurs uncombined in nature. Sulfur atoms are found in natural amino acids and vitamins. In the chemical industry, organosulfur compounds are used for fabricating rubber, fibers, and dyes, pharmaceuticals, and pesticides. Although sulfur, which is cheap and easy to handle, is a useful source of sulfur atom in functional organosulfur compounds, it is rarely used in organic synthesis. Activation of sulfur by high temperature, light irradiation, treatment with nucleophiles and electrophiles, and redox conditions often results in the formation of various active sulfur species, which complicate reactions. The development of a method that mildly activates sulfur is therefore desired. The use of transition-metal catalysts is a new method of activating sulfur under mild conditions, and, in this article, we describe the rhodium-catalyzed synthesis of various organosulfur compounds by the insertion of sulfur atoms into single bonds and by the addition of sulfur to unsaturated bond in various organic compounds. 1 Introduction 2 Sulfur Activation without using Transition Metal 3 Transition-Metal-Catalyzed Activation of Sulfur 4 Rhodium-Catalyzed Reactions using Sulfur 4.1 Rhodium-Catalyzed Sulfur Atom Exchange Reactions using Sulfur 4.2 Synthesis of Diaryl Sulfides using Rhodium-Catalyzed Exchange Reaction of Aryl Fluorides and Sulfur/Organopolysulfides 4.3 Rhodium-Catalyzed Synthesis of Isothiocyanate using Sulfur 4.4 Rhodium-Catalyzed Sulfur Addition Reaction to Alkenes for Thiiranes Synthesis 4.5 Rhodium-Catalyzed Sulfur Addition Reaction to Alkynes for 1,4-Dithiins Synthesis 5 Conclusion