One obstacle for practical glycosylations is the high cost of promoters and low-temperature equipment. This problem has been at least partially solved by using MeSCH2Cl/KI as a low-cost promoter system. MeSCH2Cl has an estimated cost of <$1/mol compared with $1741/mol for AgOTf and $633/mol for TMSOTf. This new promoter system is capable of activating various leaving groups including anomeric Cl, F, trichloroacetimidate, and acyloxy groups. Stable and easy-to-prepare anomeric benzoloxy carbohydrate donors were investigated in the glycosylations of carbohydrates, aliphatic alcohols, amino acids, steroids, and nucleoside acceptors. Most of these glycosylations were operationally simple with fast reaction rates and moderate yields of 35–79%. In addition, direct glycosylations of nucleosides using less than 2 equiv of anomeric benzoloxy donors and high stereoselective mannosylation have been achieved. From an economic point of view, this glycosylation method should be highly applicable to industrial processes.

A new type of organoprecatalyst (MeSCH2Cl/KI) for desilylation and benzylidenation reactions has been designed. Both reactions are user friendly and high yielding (71–>99%) and have fast reaction rates. The desilylation of iodo silyl ethers was achieved with no sequential etherification side reactions like those seen for reactions when using TBAF. In the application of the catalytic system to a 6-TBDMS ether of a glucoside, glucoside benzylidenations using electron-deficient benzaldehydes were achieved in 87% yield compared with the previously reported yields of 69–77%. Altogether, 14 benzylidenation reactions were realised using silyloxy alcohols and electron-deficient benzaldehydes instead of their activated acetal forms. In terms of reaction rates and yields, the order of the benzylidenations is p-fluorobenzaldehyde > benzaldehyde > p-anisaldehyde, and a possible mechanism is discussed. These experiments have preliminarily differentiated this cost-effective catalytic system from the classic Lewis acids.