Triphenylphosphine-Mediated Synthesis of Methyl 2-Aroyloxypropenoates from 2-Aroyl-2-methoxycarbonyloxiranes
摘要:
A new synthesis of several 2-aroyloxypropenoic acid methyl esters 5 by the reaction of 2-aroyl-2-methoxycarbonyloxiranes 2 with triphenylphosphine in tetrahydrofuran has been described.
CONSTRAINED COMPOUNDS AS CGRP-RECEPTOR ANTAGONISTS
申请人:Chaturvedula Prasad V.
公开号:US20070259851A1
公开(公告)日:2007-11-08
The invention encompasses constrained bicyclic and tricyclic CGRP-receptor antagonists, methods for identifying them, pharmaceutical compositions comprising them, and methods for their use in therapy for treatment of migraine and other headaches, neurogenic vasodilation, neurogenic inflammation, thermal injury, circulatory shock, flushing associated with menopause, airway inflammatory diseases, such as asthma and chronic obstructive pulmonary disease (COPD), and other conditions the treatment of which can be effected by the antagonism of CGRP-receptors.
Catalytic Asymmetric Syntheses of α-Amino and α-Hydroxyl Acid Derivatives
作者:Xiaojun Han、Xiang-Jun Jiang、Rita L. Civiello、Andrew P. Degnan、Prasad V. Chaturvedula、John E. Macor、Gene M. Dubowchik
DOI:10.1021/jo900368k
日期:2009.5.15
bromides and CH2═C(NHP)CO2Me (P = Boc or CBz) to form ArCH═C(NHP)CO2Me, which are then used for the asymmetricsyntheses of α-amino acids. We also report the first syntheses of ArCH═C(OCOAr1)CO2Me (Ar1 = Ph, 4-Cl−Ph) from ArBr and CH2═C(OCOAr1)CO2Me by the Heck reaction and subsequent successful asymmetric hydrogenation to afford α-hydroxyl esters in excellent chemical yields and good-to-excellent enantioselectivities
Synthesis of all isomers of pulcherrimine, a bitter principle in the sea urchin ovary
作者:Noriko U Sata、Ryuji Kuwahara、Yuko Murata
DOI:10.1016/s0040-4039(01)02095-0
日期:2002.1
All eight isomers of pulcherrimine, a bitter principle of the sea urchin (Hemicentrotus pulcherrimus) ovary have been synthesized, which led to revision of the absolute stereochemistry of pulcherrimine. The synthetic pulcherrimine and the 2S isomer were highly bitter at a concentration of 1.0 mM.
the methyl and ethyl esters of 2-aroyloxyacrylic acids, 2 and 3, have been prepared. Their reactivity and selectivity have been evaluated in Diels−Alder cycloadditions with unsymmetrical dienes, which generate the corresponding adducts with high regioselectivity. No significant stereoselectivity was observed in the reaction with cyclopentadiene (9), although Lewis acid catalysis improved the exo/endo
Construction of a quaternary stereogenic center by asymmetric hydroformylation: a straightforward method to prepare chiral α-quaternary amino acids
作者:Dequan Zhang、Jialin Wen、Xumu Zhang
DOI:10.1039/d2sc02139k
日期:——
The construction of chiral quaternary carbon stereocenters has been a long-standing challenge in organic chemistry. Particularly, α-quaternary aminoacids that are of high importance in biochemistry still lack a straightforward synthetic method. We here reported a hydroformylation approach to access chiral quaternary stereogenic centers, which has been a long-standing challenge in transition metal
手性季碳立体中心的构建一直是有机化学中长期存在的挑战。特别是在生物化学中具有高度重要性的α-季氨基酸仍然缺乏直接的合成方法。我们在这里报道了一种加氢甲酰化方法来获得手性四元立体中心,这一直是过渡金属催化中的一个长期挑战。在温和条件下,α,β-不饱和羧酸衍生物在铑催化剂的作用下发生加氢甲酰化,生成 α-季立体中心。采用该方法可以合成多种手性α-季氨基酸,且对映选择性良好。深入研究表明,区域选择性受到与目标 C 连接的取代基的电子特性的显着影响C键。通过NMR和DFT分析,描绘了铑/Yanphos配合物的手性环境,并在此基础上提出了底物-催化剂相互作用模型。