Thia-Michael Addition Reactions Using 2-[Bis(alkylthio)methylene]-3-oxo-N-o-tolylbutanamides as Odorless and Efficient Thiol Equivalents - Dong, Dewen; Yu, Haifeng; Ouyang, Yan; Liu, Qun; Bi, Xihe; Lu, Yumei (Synlett, 2006)