Organoboron compounds are powerful precursors of value-added organic compounds in synthetic chemistry, and transition metal-catalysed borylation has always been dominant. To avoid toxic reagents and costs associated with metal catalysts, simpler, more economical and effective approaches for delivering organoborons are highly desirable. Here, without the use of any metal catalysts, a CH3CN-involved
Herein, we report the first alkylative kineticresolution of vicinal alcohols realized by cooperative use of a chiral quaternary ammonium salt and an achiral borinic acid. In addition, a catalytic regioselective alkylation of a secondary alcohol in the presence of an unprotected primary one is presented, emphasizing the unique selectivity and potential of this ammonium borinate catalysis.
A Simple Primary Amine Catalyst for Enantioselective α-Hydroxylations and α-Fluorinations of Branched Aldehydes
作者:Michael R. Witten、Eric N. Jacobsen
DOI:10.1021/acs.orglett.5b01193
日期:2015.6.5
A new primary amine catalyst for the asymmetric a-hydroxylation and a-fluorination of alpha-branched aldehydes is described. The products of the title transformations are generated in excellent yields with high enantioselectivities. Both processes can be performed within short reaction times and on gram scale. The similarity in results obtained in both reactions, combined with computational evidence, implies a common basis for stereoinduction and the possibility of a general catalytic mechanism for a-functionalizations. Promising initial results in alpha-amination and alpha-chlorination reactions support this hypothesis.
Reaktivität und Selektivität bei der Oxidation von Styrolderivaten. III. Untersuchungen zur Oxidation von 1- und 2-Isopropenylnaphthalin
作者:W. Ya. Suprun
DOI:10.1002/prac.199733901120
日期:——
Matsumoto Takashi, Takeda Yoshio, Iwata Eiko, Sakamoto Mitsuo, Ishida Tak+, Chem. and Pharm. Bull, 42 (1994) N 6, S 1191-1197