1,2-sulfur migrations

1,2-Thio migration has emerged as a valuable synthetic tool for organic chemists. The most common route of 1,2-thio migration proceeds through a thiiranium intermediate. The latter usually proceeds stereoselectively, since substitution of a vicinal leaving group of sulfur takes place with good stereocontrol; substitution or elimination to open the thiiranium ring also proceeds stereoselectively. This and other types of 1,2-thio migration, including 1,2-thio shifts, formal 1,2-thio migration through fragmentation-recombination, [1,5] thio migration in five-membered ring systems, and radical 1,2-thio migrations are discussed in this review.