中国科学院上海有机化学研究所机构知识库
Advanced  
SIOC OpenIR  > 分析化学研究室  > 期刊论文
学科主题: 有机化学
题名: Insight into the mechanism of the asymmetric ring-opening aminolysis of 4,4-dimethyl-3,5,8-trioxabicyclo[5.1.0]octane catalyzed by titanium/BINOLate/water system: Evidence for the Ti(BINOLate)(2)-bearing active catalyst entities and the role of water
其他题名: Insight into the mechanism of the asymmetric ring-opening aminolysis of 4,4-dimethyl-3,5,8-trioxabicyclo[5.1.0]octane catalyzed by titanium/BINOLate/water system: Evidence for the Ti(BINOLate)(2)-bearing active catalyst entities and the role of water
作者: Bao HL(鲍红丽) ; Zhou J(周静) ; Wang Z(王正) ; Guo YL(郭寅龙) ; You TP(尤田耙) ; Ding KL(丁奎岭)
通讯作者: 丁奎岭
刊名: J. Am. Chem. Soc.
发表日期: 2008
卷: 130, 期:31, 页:10116-10127
收录类别: SCI
部门归属: 上海有机所; 中国科技大学
英文摘要: The mechanism of the enantioselective ring-opening aminolysis of 4,4-dimethyl-3,5,8-trioxabicyclo[5.1.0]octane with benzylamine, catalyzed by the titanium-BINOLate species generated in situ from a mixture of enantiopure BINOL (1,1'-bi-2-naphthol), Ti(OiPr)(4), and H2O in the presence of benzylamine in toluene, was investigated in detail using a combination of reaction profile measurements, nonlinear effect (NLE) studies, solution H-1 NMR analysis, electrospray ionization mass spectrometry (ESI-MS), as well as the results obtained from screening of dynamic catalyst library of complexes L-a/Ti/L-b (L-a or L-b = chiral diol ligands). The BINOL-to-titanium ratio and the presence or absence of water in the catalytic system were found to exert profound influences on both reactivity and enantioselectivity of the reaction. The NLE studies revealed that the titanium species involved in the catalysis should contain more than one BINOL unit, either within or at the periphery of the catalytic cycle. ESI-MS analysis of the catalytic systems provided strong support in favor of the mechanistic proposal that titanium complexes bearing the Ti(BINOLate)(2) moiety should be the active species responsible for the catalysis, which was further confirmed by the observation of synergistic effect of the heteroligand combinations during screening of the dynamic catalyst library. ESI-MS analysis of the reaction system indicated that water does not take part in the catalyst generation, which is an unprecedented finding in contrast to the previous mechanistic understandings in the titanium catalytic chemistry involving the participation of water. Most probably, water functions as a proton shuttle in the catalysis, facilitating the proton transfer between the reactants. Furthermore, the origin of (+)-NLE observed in the present catalytic system is rationalized on the basis of the ESI-MS analysis of the catalyst system prepared from a 1:1 pseudoracemic mixture of (S)-BINOL and (R)-3,3',6,6'-D-4-BlNOL. Finally, the reactivity differences between several couples of epoxide/amine combinations were tentatively rationalized on the basis of the arguments on their relative coordination preferences, and several other aliphatic amines were also found to efficiently ring-open the titled epoxide in excellent enantioselectivities. The results from this study are expected to shed some light on the often elusive chemistry of Ti(IV)-based catalytic systems where water or molecular sieves (or alcohols, etc.) are found to play an important yet inexplicable role and may help the search for effective asymmetric Ti(IV) catalysts for other types of reactions.
语种: 英语
相关网址: 查看原文
WOS记录号: WOS:000258080600032
Citation statistics:
内容类型: 期刊论文
URI标识: http://ir.sioc.ac.cn/handle/331003/19966
Appears in Collections:分析化学研究室_期刊论文

Files in This Item: Download All
File Name/ File Size Content Type Version Access License
2008170.pdf(541KB)----开放获取--View Download

Recommended Citation:
Bao HL,Zhou J,Wang Z,et al. Insight into the mechanism of the asymmetric ring-opening aminolysis of 4,4-dimethyl-3,5,8-trioxabicyclo[5.1.0]octane catalyzed by titanium/BINOLate/water system: Evidence for the Ti(BINOLate)(2)-bearing active catalyst entities and the role of water[J]. J. Am. Chem. Soc.,2008,130(31):10116-10127.
Service
Recommend this item
Sava as my favorate item
Show this item's statistics
Export Endnote File
Google Scholar
Similar articles in Google Scholar
[鲍红丽]'s Articles
[周静]'s Articles
[王正]'s Articles
CSDL cross search
Similar articles in CSDL Cross Search
[鲍红丽]‘s Articles
[周静]‘s Articles
[王正]‘s Articles
Related Copyright Policies
Null
Social Bookmarking
Add to CiteULike Add to Connotea Add to Del.icio.us Add to Digg Add to Reddit
文件名: 2008170.pdf
格式: Adobe PDF
此文件暂不支持浏览
所有评论 (0)
暂无评论
 
评注功能仅针对注册用户开放,请您登录
您对该条目有什么异议,请填写以下表单,管理员会尽快联系您。
内 容:
Email:  *
单位:
验证码:   刷新
您在IR的使用过程中有什么好的想法或者建议可以反馈给我们。
标 题:
 *
内 容:
Email:  *
验证码:   刷新

Items in IR are protected by copyright, with all rights reserved, unless otherwise indicated.

 

 

Valid XHTML 1.0!
Powered by CSpace