Asymmetric Synthesis of α-Aminoboronates via Rhodium-Catalyzed Enantioselective C(sp<sup>3</sup>)–H Borylation
作者:Ronald L. Reyes、Miyu Sato、Tomohiro Iwai、Masaya Sawamura
DOI:10.1021/jacs.9b12013
日期:2020.1.8
α-Aminoboronic acids, isostructural boron analogues of α-amino acids, have received much attention because of the important biomedical applications implicated for compounds containing this structure. Additionally, the inherent versatility of α-aminoboronic acids as synthetic intermediates through diverse carbon-boron bond transformations make the efficient synthesis of these compounds highly desirable
The Effect of Substituents on the Pyridine Ring in the Diastereoselective Cyclopropa- nation Reaction of Pyridinium Ylides Bear- ing an 8-Phenylmenthyl Ester Group
The reaction between β-substituted methylidenemalononitriles and the ylide from (-)-8-phenylmenthyl α-pyridiniumacetate, which affords activated cyclopropanes bearing two cyano groups and one carboxylic ester group, was examined. The trans isomer was obtained in up to 91:9 diastereoselectivity under optimized solvent conditions for the t-butyl substituted substrate. The selectivity increased to 96:4