共查询到19条相似文献,搜索用时 78 毫秒
1.
2.
Baeyer-Villiger反应是有机化学基本反应之一,但是催化不对称Baeyer-Villiger反应的研究尚处于起步阶段。本文按手性配体的不同,评述了手性金属络合物催化不对称Baeyer-Villiger反应的研究,特别是由外消旋或前手性酮制备光学活性内酯的研究进展。 相似文献
3.
4.
5.
6.
奎宁与钴(Ⅱ)手性络合物用于前手性酮的不对称催化还原 总被引:2,自引:0,他引:2
奎宁与钴(Ⅱ)手性络合物用于前手性酮的不对称催化还原刘湘*李纪国张正(无锡轻工大学化工系无锡214036)(南京大学化学系南京)关键词手性络合物,不对称还原,前手性芳香酮1996-10-25收稿,1997-04-22修回前手性酮的不对称催化还原作为光... 相似文献
7.
8.
各种手性三齿席夫碱与金属(钛, 铬, 钒, 铁, 铜, 铝)形成的络合物,在催化醛的硅腈化、Diels-Alder、Aldol、杂ene、硫化物的氧化等不对称反应中具有良好的催化活性和对映选择性;其中一些催化体系已成功的应用于天然产物的全合成中,该研究取得了系统性的研究成果。本文综述了手性三齿席夫碱金属络合物在不对称催化反应中的研究进展,同时,探讨了催化剂结构和反应条件对其催化活性和对映选择性的影响。 相似文献
9.
金鸡纳生物碱的金属络合物用于苯乙酮的不对称催化还原 总被引:3,自引:0,他引:3
金鸡纳生物碱的金属络合物用于苯乙酮的不对称催化还原刘湘(无锡轻工大学化工系无锡214036)李纪国张正(南京大学化学系南京210093)关键词金鸡纳生物碱手性络合物不对称还原苯乙酮分类号O643.32近10多年来,前手性酮的不对称还原反应作为制备光学... 相似文献
10.
11.
FENG Xiaoming 《高等学校化学研究》2001,17(3)
Chiral titanium complexes is very importance catalyst to asymmetric catalytic reactions. A series of catalytic systems based on titanium-chiral ligands complexes has been reported. This presentation will discuss some of our recent progress on asymmetric catalytic reactions catalyzed by chiral titanium complexes. 相似文献
12.
Chun‐Xiang Zhuo Prof. Dr. Wei Zhang Prof. Dr. Shu‐Li You 《Angewandte Chemie (International ed. in English)》2012,51(51):12662-12686
This Review summarizes the development of catalytic asymmetric dearomatization (CADA) reactions. The CADA reactions discussed herein include oxidative dearomatization reactions, dearomatization by Diels–Alder and related reactions, the alkylative dearomatization of electron‐rich arenes, transition‐metal‐catalyzed dearomatization reactions, cascade sequences involving asymmetric dearomatization as the key step, and nucleophilic dearomatization reactions of pyridinium derivatives. Asymmetric dearomatization reactions with chiral auxiliaries and catalytic asymmetric reactions of dearomatized substrates are also briefly introduced. This Review intends to provide a concept for catalytic asymmetric dearomatization. 相似文献
13.
Yang‐Zi Liu Zhongao Wang Zesheng Huang Xing Zheng Wu‐Lin Yang Wei‐Ping Deng 《Angewandte Chemie (International ed. in English)》2020,59(3):1238-1242
The palladium‐catalyzed asymmetric [4+3] cyclization of trimethylenemethane donors with benzofuran‐derived azadienes furnishes chiral benzofuro[3,2‐b]azepine frameworks in high yields (up to 98 %) with exclusive regioselectivities and excellent stereoselectivities (up to >20:1 d.r., >99 % ee). This catalytic asymmetric [4+3] cyclization of Pd‐trimethylenemethane can enrich the arsenal of Pd‐TMM reactions in organic synthesis. In addition, this strategy provides an alternative approach to chiral azepines by a transition‐metal‐catalyzed asymmetric [4+3] cyclization. 相似文献
14.
手性钛配合物催化不对称反应研究 总被引:4,自引:0,他引:4
手性钛配合物是一类很有用的手性催化剂,在许多反应中显示出了良好的催化活性和高的对映选择性。在我们研究的系列反应中,发现手性钛配合物是一类优良的手性催化剂,其中不对称催化杂Diels-Alder反应制备二氢吡喃酮(99%ee),不对称催化硫醚氧化成亚砜反应(96%ee)和不对称催化硅腈化反应(87%ee),都获得了好的催化活性和高的对映选择性。我们对以上反应中其催化剂的用量、溶剂、催化剂浓度和抗衡离子的Lewis酸碱性、底物的结构与对映选择性的关系、催化循环机理等进行了较系统、深入的研究,发现非共价相互作用和分子识别现象在不对称催化反应中显示出重要的作用,为进一步设计新的手性催化剂,发展不对称催化反应提供了基础数据。 相似文献
15.
Control of stereochemistry during aldol addition reactions has attracted considerable interest over the years as the aldol reaction is one of the most fundamental tools for the construction of new carbon-carbon bonds. Several strategies have been implemented whereby eventually any single possible stereoisomeric aldol product can be accessed by choosing the appropriate procedure. With earlier methods, stoichiometric quantities of chiral reagents were required for efficient asymmetric induction, with the auxiliary most often attached covalently to the substrate carbonyl. Lewis acid catalyzed addition reactions of silyl enolates to aldehydes (Mukaiyama reaction) later opened the way for catalytic asymmetric induction. In the last few years, both chiral metal complexes and small chiral organic molecules have been found to catalyse the direct aldol addition of unmodified ketones to aldehydes with relatively high chemical and stereochemical efficiency. These techniques along with the more recent developments in the area are discussed in this tutorial review. 相似文献
16.
FU Bin DU Da-Ming WANG Jian-Bo 《有机化学》2003,23(Z1):27-27
Over the last decade, C2-symmetric chiral oxazoline metal complexes have been recognized as an effective classof chiral catalyst in a variety of transition metal catalyzed asymmetric reactions. [1] High catalytic activities and enantiomeric excesses have been obtained using C2-symmetric chiral ligands in conjunction with suitable transition metal ion, for example, the hydrosilylation of ketone, allylic alkylation, Michael addition, Diels-Alder cycloaddition, and cyclopropanation. Thus, the design and synthesis of new chiral oxazoline ligands have inspired many scientists to work with great efforts. 相似文献
17.
Lu‐Lu Li Du Ding Jin Song Zhi‐Yong Han Liu‐Zhu Gong 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(23):7729-7733
A general strategy for the design of asymmetric cascade reactions using readily available halides and carbon monoxide (CO) as substrates is developed. The key is the catalytic generation of C1‐ammonium enolates for the subsequent asymmetric cascade reactions through the combination of palladium‐catalyzed carbonylation and chiral Lewis base catalysis. Utilizing this strategy, we have established asymmetric formal [1+1+4] and [1+1+2] reactions to afford chiral dihydropyridones and β‐lactams with high yields and high enantio‐ and diastereoselectivities. 相似文献
18.
19.
The very recent advances in chiral phosphoric acids (CPAs) catalyzed asymmetric reactions are discussed. 相似文献