Publications by authors named "Kou-Sen Cao"

The first highly enantioselective catalytic protocol for selective manipulation of tetrol benzylidene acetals through chiral phosphoric acid mediated oxidative desymmetrization is reported. This efficient approach provides a general access to vicinal all-carbon quaternary stereogenic center structural motifs, as well as structures containing vicinal tertiary and quaternary stereocenters enantioselectively. The synthetic utility has been furthermore demonstrated by transformations and gram-scale processes.

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The first example of arylboronic acid catalyzed [4 + 3] cycloaddition reaction is reported. 3,5-Bis-(trifluoromethyl) phenylboronic acid is shown to be the best catalyst in this reaction. The method has also enabled the preparation of cyclohepta[b]benzofurans and cyclohepta[b]indoles in excellent yields.

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A highly enantioselective catalytic protocol for the desymmetrization of a wide variety of 2-substituted and 2,2-disubstituted 1,3-diols is reported. This reaction proceeds through the formation of an "ortho ester" intermediate via oxidation of 1,3-diol benzylidene acetal by dimethyldioxirane (DMDO) and the subsequent proton transfer catalyzed by chiral phosphoric acid (CPA). The mechanism and origins of enantioselectivity of this reaction are identified using DFT calculations.

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A family of novel linear 1,10-phenanthroline-based (A-D-A-D-A) and oligothiophene-based (A-D-D-D-(D)-A) heterocyclic aromatic fluorescence compounds having N-containing imidazole and pyridine tails with effective π-conjugated systems, prepared by the combination of carbon-carbon (C-C) bond and carbon-nitrogen (C-N) bond cross-coupling reactions, is described. They have molecular lengths of more than 2.30 nm in the cases of 4, 6, 9, and 26, various D-A spacers, and certain N-coordination sites (phen, imidazole, and pyridine).

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