1085789-46-3Relevant academic research and scientific papers
An experimental and theoretical study on the remarkable influence of protecting groups on the selectivity of addition of amines to vinyl sulfone-modified hex-2-enopyranosides
Bhattacharya, Rahul,Kesharwani, Manoj K.,Manna, Chinmoy,Ganguly, Bishwajit,Suresh, Cheravakattu G.,Pathak, Tanmaya
scheme or table, p. 303 - 314 (2010/03/30)
(Chemical Equation Presented) Although phenylmethylene-protected vinyl sulfone-modified carbohydrate 2α reacts with both primary and secondary amines inMichael fashion to afford aminated products, only primary amines react with the dibenzyl-protected 3α, 6-O-trityl-protected 4α, and unprotected 5α, highlighting for the first time the remarkable influence of protecting groups on the reaction patterns of vinyl sulfonemodified carbohydrates. The quantum chemical calculations suggest that the Michael addition of amines and proton transfer to vinyl sulfone-modified carbohydrates 2α and 5α are possible via relay process in a concerted mechanism. These calculations reveal that the addition of primary amines to vinyl sulfone-modified carbohydrate is preferential due to the low activation energy barriers, whereas the addition of secondary amines has relatively higher activation energy barriers. The theoretical conclusions are in line with the experimental observations.
Diastereoselective addition of planar N-heterocycles to vinyl sulfone-modified carbohydrates: a new route to isonucleosides
Sanki, Aditya K.,Bhattacharya, Rahul,Atta, Ananta Kumar,Suresh, Cheravakkattu G.,Pathak, Tanmaya
, p. 10406 - 10416 (2008/12/22)
Michael-type addition reactions of planar N-heterocycles at the C-2 positions of vinyl sulfone-modified carbohydrates provide an efficient and general route for the carbon-N-heterocycle bond formation. Therefore, the addition pattern of planar heterocycles, such as imidazole, triazole, thymine, and adenine to 3-C-phenylsulfonyl-hex-2-enopyranosides (1α/1β) and 3-C-p-toluenesulfonyl-pent-2-enofuranosides (2α/2β) was studied for developing a general methodology for the synthesis of new classes of isonucleosides possessing a carbon-N-heterocycle linkage at C-2 positions of furanosyl and pyranosyl sugars. To a great extent, the anomeric configurations of the starting vinyl sulfones play crucial roles in deciding the diastereoselectivity of addition of heterocycles. However, the trityl protected 3-C-p-toluenesulfonyl-hex-2-enopyranosides (33α/33β) were judged to be more practical starting materials for desulfonylation and deprotection for the synthesis of a new class of thymine and adenine deoxyisonucleosides.
