54889-80-4Relevant academic research and scientific papers
Metal trifluoromethanesulfonate-catalyzed regioselective reductive ring opening of benzylidene acetals
Shie, Chi-Rung,Tzeng, Zheng-Hao,Wang, Cheng-Chung,Hung, Shang-Cheng
experimental part, p. 510 - 523 (2010/06/16)
A systematic study of various metal trifluoromethanesulfonates as efficient catalysts in the regioselective reductive ring opening of benzylidene acetals is described, including the effects of solvents, reducing agents, and temperature. These catalysts are found to be effective in cleaving the 4,6-O-acetal rings of hexopyranosides at either O4 or O6, respectively. When used in conjunction with a 1 M solution of BH3.THF in THF without extra addition of any solvent, it affects the ring fission at the O6 position to generate the corresponding primary alcohols, whereas O4-opening takes place in acetonitrile in the presence of dimethylethylsilane as the reductant leading to the secondary hydroxyl derivatives in high selectivity and yields. These methodologies can be applied to a wide range of substrates containing various functional groups.
Cu(OTf)2 as an efficient and dual-purpose catalyst in the regioselective reductive ring opening of benzylidene acetals
Shie, Chi-Rung,Tzeng, Zheng-Hao,Kulkarni, Suvarn S.,Uang, Biing-Jiun,Hsu, Ching-Yun,Hung, Shang-Cheng
, p. 1665 - 1668 (2007/10/03)
(Chemical Equation Presented) Reducing the choices. Cu(OTf)2 is an efficient and dual-purpose catalyst for the highly regioselective reductive ring openings of benzylidene acetals with either BH3 or Me 2EtSiH to give the corresponding primary and secondary alcohols (see scheme). Isotope studies have confirmed that both modes of ring cleavage proceed by an SN1 reaction pathway when borane or silane attack the acetal carbon center.
