Catalytic Asymmetric Cyano-Ethoxycarbonylation Reaction of Aldehydes Using a Novel <i>C</i><sub>2</sub>-Symmetric Chiral <i>N</i>,<i>N</i>′-Dioxide Titanium Complex
作者:Xiaoming Feng、Qinghan Li、Lu Chang、Xiaohua Liu
DOI:10.1055/s-2006-947322
日期:2006.7
The asymmetric addition of ethyl cyanoformate to a range of aldehydes was efficiently catalyzed by a easily prepared C 2 -symmetric chiral N,N'-dioxide-Ti(IV) complex in high yields with up to 90% ee under mild conditions. A linear effect between the enantiopurity of the ligand and the enantiopurity of the product was observed.
氰基甲酸乙酯与一系列醛的不对称加成被一种易于制备的 C 2 -对称手性 N,N'-二氧化钛-Ti(IV) 配合物有效催化,在温和条件下的收率高达 90%。观察到配体的对映纯度和产物的对映纯度之间存在线性效应。
Asymmetric Three-Component Reaction for the Synthesis of Tetrasubstituted Allenoates via Allenoate-Copper Intermediates
作者:Yu Tang、Jian Xu、Jian Yang、Lili Lin、Xiaoming Feng、Xiaohua Liu
DOI:10.1016/j.chempr.2018.04.012
日期:2018.7
three-component reaction of α-diazoesters with terminal alkynes and isatins was achieved. This one-pot synthesis gave rise to axially chiral tetrasubstituted allenoates bearing a stereogenic center. The chiral guanidinium salt/CuBr/YBr3 catalytic system proved efficient and highly diastereo- and enantioselective for a wide range of alkynes, aromatic α-diazoesters, and isatins under mild reaction conditions
The reactions of salicylaldimines with electron‐rich alkenes (2,3‐dihydro‐2H‐furan and 3,4‐dihydro‐2H‐pyran) catalyzed by N,N′‐dioxide–Sc(OTf)3complexes were investigated. The methodology was successfully applied to the asymmetricsynthesis of cis‐4‐aminobenzopyran derivatives. Excellent yields, diastereo‐ and enantioselectivities were observed for a broad range of substrates under mild conditions
bisformamides have been shown to catalyze the asymmetric one-pot, three-component Streckerreaction, which produced the α-amino nitriles in excellent yields (up to 99%) with good enantioselectivities (up to 86% ee). Optically pure products could be obtained after a single recrystallization. A possible transition state (TS1) has been proposed to explain the origin of asymmetric inductivity and reactivity according
C 2对称的手性双甲酰胺已显示出催化不对称的一锅,三组分Strecker反应,该反应以优异的对映体选择性(高达86%ee)以优异的收率(高达99%)产生了α-氨基腈。在单次重结晶后可获得光学纯的产物。根据在B3LYP / 6-31G(d)水平下优化的催化剂2a的几何形状和产物4a的绝对构型,已经提出了一种可能的过渡态(TS 1)来解释不对称感应性和反应性的起源。
Synthesis and anticancer activity of conformationally constrained Smac mimetics containing pseudo β turns
作者:Sachin B. Baravkar、Mahendra A. Wagh、Debasish Paul、Manas Santra、Gangadhar J. Sanjayan
DOI:10.1016/j.tetlet.2018.08.016
日期:2018.9
Herein, we report synthesis and in vitro anticancer activity of conformationally constrained Smac mimetics containing reverse turn inducing motifs “Ant-Pro” and “sAnt-Pro”. The synthesis of Smac analogs with diverse hydrophobic groups at the C-terminus was carried out using solution phase peptide synthesis. The synthesis of Ant-Pro containing analogs 3a–j was carried out by ring opening of benzoxazinones