Reduction of Sulfur Dioxide and Carbon Dioxide with Benzoin Carbanion. Oxygen Transfer from Products Formed by the Reduction of Sulfur Dioxide to 7,7,8,8-Tetracyanoquinodimethane

Article abstract of DOI:10.1246/bcsj.61.3951

A reaction of sulfur dioxide (SO2) with benzoin carbanion (the lithium salt of benzoin dianion, 1) in tetrahydrofuran (THF) gave a mixture of benzyl (2) and benzoin (3) in yields of 83 and 17 percent, respectively, irrespective of the reaction temperature between -78 and 25 deg C.The reaction of carbon dioxide (CO2) with 1 in THF gave a mixture of 2 and 3 accompanied by the formation of a small amount of lithium benzoate (4).The proportion of 2 in a mixture of 2 and 3 formed in the reaction of CO2 with 1 were 49, 30, and 20percent at -78, -22, and 25 deg C, respectively.The reaction of SO2 with 1 in the presence of 7,7,8,8-tetracyanoquinodimethane (TCNQ) gave oligomers of TCNQ with a yield of 60percent, in which some parts of the cyano groups were transformed to carboxylato groups.