Organosulfur compounds play key roles in many biological structures and functions: two of the 21 proteinogenic amino acids contain sulfur, and seven of the 10 best-selling drugs in the US in 2009 were organosulfur compounds. Glutathione plays a crucial role in primary metabolism, and (R)- thioterpineol (limonenethiol or “grapefruit mercaptan”) is an important and extremely powerful flavour compound, providing the distinctive taste of grapefruit. The consequent need to prepare and manipulate enantiomerically pure organosulfur species has powered the development of asymmetric synthetic methods leading to various classes of organic sulfur compounds, with chirality residing at sulfur, at carbon or at both.
Enantiomerically pure tertiary thiols provide a major synthetic challenge, and despite the importance of chiral sulfur-containing compounds in biological and medicinal chemistry, surprisingly few effective methods are suitable for the asymmetric synthesis of tertiary thiols. This review details the most practical of the methods available.
The article is published online in Beilstein Journal of Organic Chemistry and is free to access.