共查询到18条相似文献,搜索用时 93 毫秒
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尽管已报道了多种结构类型的手性单或双噁唑啉, 但手性多噁唑啉的合成及其应用的文献报道比较少. 本工作以多元羧酸为原料, 与手性2-氨基-1-丁醇经一步反应合成了8个手性多噁唑啉, 产率为89%~98%, 其结构经1 H NMR谱、IR谱、MS谱和元素分析确证. 相似文献
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新型C2对称的手性双噁唑啉的合成及与钛催化二乙基锌对醛的不对称加成反应 总被引:2,自引:1,他引:2
合成了6个具有2对称性的类卟啉手性双噁唑啉配体,将这些化合物与Ti(OPr-i)。配位应用于二乙基锌对芳香醛的不对称加成反应,获得了较高的化学产率和中等程度的ee值(55%). 相似文献
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手性亚砜的合成及其在不对称合成中的应用 总被引:1,自引:0,他引:1
本文综述了手性亚砜的合成。由于亚砜结构上的特征以及与金属离子的络合能力,使手性亚砜在不对称合成中具有强烈的诱导作用,使它成为进行不对称合成的一个手段。本文列举了它在不对称合成中的应用情况。 相似文献
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手性胺类化合物广泛存在于天然产物、药物分子和多功能材料中,而且作为重要中间体、催化剂和手性辅剂在有机合成中也有广泛的应用,因此,发展高效的方法合成各种手性胺化合物及相应的骨架结构具有重要的科学意义和应用价值.有机硼试剂、胺和羰基化合物参与的不对称Petasis三组分反应是构建手性胺及其衍生物最简洁、高效的方法之一.近年来,利用该策略来构建手性胺类化合物引起了广泛的关注.文章综述了不对称Petasis反应合成手性胺类化合物的近期研究进展,主要包括手性胺源、手性羰基化合物和手性硼试剂参与的底物诱导的不对称Petasis反应,以及手性催化剂促进的不对称Petasis反应,并对该领域的挑战和未来发展方向进行简要讨论. 相似文献
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近年来,用聚合物负载的手性催化剂和手性试剂完成的不对称合成反应主要集中在潜手性酮的不对称还原反应;烯烃的不对称双羟基化反应;烯烃的不对称环氧化反应;不对称Diels-Alder反应和饱和碳原子上的不对称取代反应。就近十年来聚合物负载手性催化剂和手性试剂的合成及应用进行了讨论。 相似文献
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应用手性高分子试剂和催化剂的不对称有机合成反应 总被引:2,自引:0,他引:2
不对称有机合成是有机化学的前沿课题之一.本文综述了应用手性高分子试剂和催化剂对潜手性化合物通过不对称氧化、还原、烷基化、加成反应进行不对称合成的进展情况. 相似文献
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Various ligands, such as (Z)‐1‐phenyl‐2‐[(4S)‐4‐phenyl‐4,5‐dihydro‐1,3‐oxazol‐2‐yl]ethen‐1‐ol ((S)‐ 1a ) and (Z)‐1‐phenyl‐2‐[(4S)‐4‐phenyl‐4,5‐dihydro‐1,3‐thiazol‐2‐yl]ethen‐1‐ol ((S)‐ 1c ), were investigated as auxiliaries for the asymmetric synthesis of chiral ruthenium(II) complexes. The reaction of these chiral auxiliary ligands with [RuCl2(dmso)4], 2,2′‐bipyridine (bpy, 2.2 equiv), and triethylamine (10 equiv) in DMF/PhCl (1:8) at 140 °C for several hours diastereoselectively provided the complexes Λ‐[Ru(bpy)2{(S)‐ 1a ? H}] (Λ‐(S)‐ 2a , 52 % yield, 56:1 d.r.) and Λ‐[Ru(bpy)2{(S)‐ 1c ? H}] (Λ‐(S)‐ 2c , 48 % yield, >100:1 d.r.) in a single step after purification. Both Λ‐(S)‐ 2a and Λ‐(S)‐ 2c could be converted into Λ‐[Ru(bpy)3](PF6)2 by replacing the bidentate enolato ligands with bpy, under retention of configuration, induced by either NH4PF6 as a weak acid (from Λ‐(S)‐ 2a : 73 % yield, 22:1 e.r.; from Λ‐(S)‐ 2c : 77 % yield, 22:1 e.r.), TFA as a strong acid (from Λ‐(S)‐ 2a : 72 % yield, 52:1 e.r.; from Λ‐(S)‐ 2c : 85 % yield, 25:1 e.r.), methylation with Meerwein′s salt (from Λ‐(S)‐ 2a : 59 % yield, 46:1 e.r.; from Λ‐(S)‐ 2c : 86 % yield, 37:1 e.r.), ozonolysis (from Λ‐(S)‐ 2a : 56 % yield, 22:1 e.r.; from Λ‐(S)‐ 2c : 43 % yield, 6.3:1 e.r.), or oxidation with a peroxy acid (from Λ‐(S)‐ 2a : 72 % yield, 45:1 e.r.; from Λ‐(S)‐ 2c : 79 % yield, 8.5:1 e.r.). This study shows that, except for the reaction with NH4PF6, oxazoline‐enolato complex Λ‐(S)‐ 2a provides Λ‐[Ru(bpy)3](PF6)2 with higher enantioselectivities than analogous thiazoline‐enolato complex Λ‐(S)‐ 2c , which might be due to the higher coordinative stability of the thiazoline‐enolato complex, thus requiring more prolonged reaction times. Thus, this study provides attractive new avenues for the asymmetric synthesis of non‐racemic ruthenium(II)‐polypyridyl complexes without the need for using a strong acid or a strong methylating reagent, as has been the case in all previously reported auxiliary methods from our group. 相似文献
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Prof. Dr. Zhi-Yong Han Prof. Dr. Liu-Zhu Gong 《Chemical record (New York, N.Y.)》2023,23(4):e202300049
Asymmetric Brønsted acid catalysis has been recognized as a powerful concept for asymmetric synthesis. In the process of pursuing more robust and highly effective chiral Brønsted acid catalysts, chiral bisphosphoric acids have received much attention in the last two decades. Their unique catalytic properties are mainly attributed to the inherent intramolecular hydrogen bonding interactions that could increase the overall acidity and tune the conformation property. Integrating hydrogen bonding into the catalyst design, quite a few structurally unique and effective bisphosphoric acids have been synthesized, which frequently exhibited superior selectivity in a broad range of asymmetric transformations. This review summarizes the status quo of chiral bisphosphoric acid catalysts and their applications in catalyzing asymmetric transformations. 相似文献