Synthesis of modified partial structures of the bacterial cell wall. 1. Lipopeptides containing nonproteinogenic amino acids
摘要:
Two stereoisomeric lipopeptides 1 and 2 which can be regarded as modified peptidoglycans have been synthesized by using three different reaction sequences. The ene reaction of the alpha-allylated dipeptide 12 with butyl glyoxylate was used as a key step. The required enantiomerically pure substrates 9, 10, and 23 were obtained by enzymatic hydrolysis of the corresponding racemic alpha-allylated esters. The absolute configuration of both stereoisomers 1 and 2 was assigned by oxidative cleavage of the double bond in 18 and 19 followed by comparison of the esterified degradation products 28 and 29 with samples of authentic configuration, derived from (R)- and (S)-malic acid.
Single‐Site Molybdenum Catalyst for the Synthesis of Fumarate
作者:Huifang Jiang、Rui Lu、Xiaoqin Si、Xiaolin Luo、Jie Xu、Fang Lu
DOI:10.1002/cctc.201900332
日期:2019.9.5
pyridine nitrogen and oxygen in hydroxyl of 8‐hydroxyquinoline coordinated with Mo atom. The crystal catalyst was stabilized by π‐π stacking interaction and hydrogen bonds to form isolated Mo specie. The single‐site molybdenumcatalyst exhibited excellent catalytic performance in didehydroxylation reactions with highselectively of dibutyl fumarate (86 %) product at mild reaction condition. Deuterium isotopic