Mlynarski, J.; Gut, B.
Organocatalytic Synthesis of Carbohydrates (Tutorial Review)
Chem. Soc. Rev. 2012 41 587-596 (link to page)
The key role of
Buda, S.; Nawój, M.; Gołębiowska, P.; Dyduch, K.; Michalak, A.; Mlynarski, J.
Application of 2-Substituted Benzyl Groups in Stereoselective Glycosylation
J. Org. Chem. 2015 80 770-780 (link to page)
The use of 2-O-(2-nitrobenzyl) and 2-O-(2-cyanobenzyl) groups control stereoselective formation of 1,2-trans-glycosidic linkage via arming participation effect. Observed stereoselectivity arise likely from the intramolecular formation of cyclic intermediate between electron rich substituent and donor oxacarbenium ion providing expected facial selectivity for the attack of the glycoside acceptor. The stereodirecting effect of the 2-nitro- and 2-cyanobenzyl groups attached at remote position (C-3, C-4, and C-6) of donor molecule have also been investigated. To prove postulated mechanism based on participation effect of 2-substituted benzyl groups in the glycosylation stereoselectivity we used DFT theoretical calculation methodology.