手性Salen-Cu(Ⅱ)和唑啉-Cu(Ⅱ)配合物催化2-苯基环己酮的不对称Baeyer-Villiger反应研究

对一系列手性Salen和唑啉配体与中心金属Cu(Ⅱ)的配合物催化2-苯基环己酮的不对称Baeyer-Villiger反应进行了研究,设计和合成了新型手性配体Ⅲ,Ⅳ, Ⅴ,对配合物Ⅴ-Cu(Ⅱ)进行了单晶X射线衍射分析. 并考察了助氧化剂、溶剂等对反应活性和选择性的影响.     

手性Salen—Cu（II）和Wu唑啉—Cu（II）配合物催化2—苯基环已酮的不对称Baeyer—

对一系列手性Salen和Wu唑啉配体与中心金属（Cu（II）的配合物催化2－苯基环已酮的不对称Baeyer-Villiger反应进行了研究,设计和合成了新型手性配体III,IV,V,对配合物V－Cu（II）进行了单晶X射线衍射分析,并考察了助氧化剂,溶剂等对反应活性和选择性的影响。     

(R)-TTCA·K催化下环己酮与丙烯腈的加成反应

手性催化剂催化下的不对称合成反应是近年来不对称合成研究中受到重视的领域，如在手性催化剂如，在手性冠醚，手性镧配合物、手性硒、手性铑及手性脯氨酸铷盐等催化下，醛、酮与二烃基锌形成手性醇和不对称羟醛缩合反应等，催化下通过Michael加成反应合成手性化合物的方法近年来也有报道，     

有机催化不对称[4+2]环加成反应*

有机催化不对称合成反应是目前国内外研究最为活跃的领域之一。不对称[4+2]环加成（Diels-Alder）反应是合成光学活性环状化合物的有效手段,目前报道的催化不对称Diels-Alder反应的有机催化剂主要有手性咪唑啉酮、手性Br?nsted酸、手性伯胺、金鸡纳碱衍生物等。本文对各类有机催化剂在有机催化不对称Diels-Alder反应中的应用研究进展,以及不对称诱导反应的机理进行了评述。     

手性BrФnsted酸催化双氧水与3-取代环丁酮的不对称Baeyer—Villiger反应

Baeyer-Villiger（BV）反应在有机合成中被应用广泛．以环境友好的H2O2水溶液（30％）作为氧化剂是BV反应长期追求的目标（Chem．Rev．2004,105,4105～4123）．金属或有机小分子催化的不对称BV反应已有很多报道,但存在的挑战性问题是选择性控制困难,如对于3-取代环丁酮的反应,还没有催化剂能够获得〉86％的对映选择性,而使用H2O2水溶液作为氧化剂的不对称BV反应报道更少．中国科学院上海有机化学研究所丁奎岭等以30％的H2O2水溶液作为氧化剂,实现了手性BrФnsted酸1催化3-取代环丁酮的不对称Baeyer-Villiger反应,以91％～99％的产率和55％～A93％ee值得到相应的γ-丁内酯衍生物,这一结果是除酶以外的所有化学催化剂中最好的．该催化反应体系代表了手性磷酸催化的一个新反应类型．     

亚砜及亚磺酰胺类配体催化不对称反应的新进展

亚砜及亚磺酰胺类化合物作为手性配体催化不对称反应是目前研究最为活跃的领域之一,苯环骨架以及链状骨架的亚砜及亚磺酰胺类手性配体相继成功地用于不对称反应中.主要综述了近年来含亚砜及亚磺酰胺类的手性配体催化不对称反应的研究进展.     

R-沙美特罗的合成方法

近年来手性沙美特罗的合成方法有微生物催化、不对称氢化、CBS(Corey-Bakshi-Shibata)还原反应及不对称Henry反应、手性(Salen)Co试剂催化的HKR(末端环氧不对称水解动力学)拆分反应等。对这些方法进行比较,结果表明,不对称催化合成由于其反应收率高、反应产物光学纯度高、操作容易控制,在目前手性药物的合成中处于主导地位。此外酶催化不对称合成、手性辅基诱导的对映选择性合成等方法也是有效的途径。     

面包酵母在催化不对称合成中的应用

介绍了当前国内外在以面包酵母为催化剂不对称催化合成手性化合物的研究情况，重点介绍了面包酵母催化各类潜手性羰基的不对称还原、潜手性碳一碳双键的不对称加成和碳一碳键形成的反应情况，讨论了各种提高酵母催化不对称合成反应立体选择性的方法，对酵母催化不对称合成有关生物学方面的研究进行了简单的介绍。     

催化不对称Michalel加成反应的新进展

总结了近年催化不对称Michael加成反应的新方法，包括手性金属络合物催化 的反应，呈手性Lewis酸性的手性金属络合物促进的不对称加成，手性冠醚络合物 催化的反应及其它催化反应。     

手性季鏻盐相转移催化剂在不对称反应中的应用

手性相转移催化是不对称催化领域的重要分支之一,扮演着越来越重要的角色。本论文综述了几类新型手性季鏻盐催化剂的设计合成,及其在催化不对称Henry反应、不对称氢磷酰化反应、不对称烷基化反应、不对称Michael加成反应、不对称Mannich反应、不对称aldol反应、不对称质子化反应及不对称胺化反应中的催化活性和对映选择性,重点介绍了不同催化剂和反应底物之间立体效应和电子效应的影响,并对手性季鏻盐催化剂的发展进行了展望。     

Blending Baeyer-Villiger monooxygenases: using a robust BVMO as a scaffold for creating chimeric enzymes with novel catalytic properties

The thermostable Baeyer-Villiger monooxygenase (BVMO) phenylacetone monooxygenase (PAMO) is used as a scaffold to introduce novel selectivities from other BVMOs or the metagenome by structure-inspired subdomain exchanges. This yields biocatalysts with new preferences in the oxidation of sulfides and the Baeyer-Villiger oxidation of ketones, all while maintaining most of the original thermostability.     

Enantioselective synthesis of gamma-aryl-gamma-butyrolactones by sequential asymmetric epoxidation, ring expansion, and Baeyer-Villiger oxidation

This paper describes an enantioselective synthesis of gamma-butyrolactones, using the N-tolyl-substituted oxazolidinone-containing ketone as catalyst and Oxone as oxidant via a sequential asymmetric epoxidation of benzylidenecyclopropanes, ring expansion, and Baeyer-Villiger oxidation. Up to 91% ee was obtained. Optically active cyclobutanones can also be obtained by suppressing the Baeyer-Villiger oxidation with use of more ketone catalyst and less Oxone.     

Lathyranoic acid A: first secolathyrane diterpenoid in nature from Euphorbia lathyris

[structures: see text] Lathyranoic acid A (1), the first secolathyrane diterpenoid with an unprecedented skeleton, and a new diterpenoid Euphorbia factor L11 (2) were isolated from the seeds of Euphorbia lathyris. Their structures were elucidated by spectroscopic analysis and chemical methods. A biogenetic route involving an enzymatic Baeyer-Villiger oxidation as the key step was postulated for the transformation of 2 to 1 and mimicked by an unusual chemical Baeyer-Villiger oxidation.     

An unusual effect of selenium substituents on the regiochemistry of a baeyer-villiger rearrangement

The regioselectivity of a Baeyer-Villiger oxidation of a cyclobutanone is dependent upon the oxidation state of a proximal selenium substituent.     

Construction of the Tricyclo

Histrionicotoxin derivatives have long been attractive targets for synthetic chemists as a result of their useful neurophysical properties, low natural abundance, and the unique structural features of the azaspiro[5.5]undecane ring system. Utilizing our tandem pinacol rearrangement-ene strategy and regiospecific Baeyer-Villiger oxidation as key steps, we have successfully synthesized an advanced synthetic intermediate, spiro[5.4]decane 4, which has previously been converted to (+/-)-perhydrohistrionicotoxin (5b). Pinacol rearrangement of simple Diels-Alder derived bicyclo[2.2.2]octene system 2a, followed by an ene reaction, led to the efficient formation of the highly fuctionalized tricyclo[5.3.1.0(1,5)]undecane system 1a. This tricyclic system 1a was selectively transformed into spiro[5. 4]decane system 4 via a regiospecific Baeyer-Villiger oxidation reaction. We also report the results of systematic studies of Baeyer-Villiger oxidation reactions of tricyclo[5.3.1.0(1, 5)]undecanone systems to elucidate the origin of the regioselectivity of this process.     

Microreactors for oxidations using fluorine

Continuous flow gas-liquid thin film microreactors have been effectively used for the oxidation of alcohols and Baeyer-Villiger oxidation of ketones using elemental fluorine.     

Torsional effects in the baeyer-villiger oxidation

The regioselectivity in the Baeyer-Villiger oxidation of tetracyclic ketones 1A–C have been interpreted in terms of torsional effects.     

Enhanced shape selective catalysis of mixed cyclic ketones in aerobic Baeyer-Villiger oxidation with magnetic Cu-Fe3O4 supported mesoporous silica microspheres

Various strategies have been developed to improve the conversion for the Baeyer-Villiger oxidation. However, the catalytic effects of the Baeyer-Villiger oxidation for the mixed ketones are rarely reported, though it is also important for the natural and industrial separation processes. In this report, magnetite Cu modified Fe₃O₄ supported mesoporous silica microspheres (Cu-Fe₃O₄@mSiO₂) have been successfully synthesized by two step direct hydrothermal method (DHT). Over 99% of cyclohexanone conversion was obtained with mild air oxidation and benzaldehyde as sacrificing agent over Cu-Fe₃O₄@mSiO₂. The catalytic system also shows higher conversion rates for small molecular ketones in the mixed ketone reactants, which was attributed to the enhanced mass transfer effect and Fe-Cu composite active sites in the magnetite mesoporous silica microspheres. The catalyst could be recycled for four times with similar catalytic performance, which shows enhanced shape selectivity in aerobic Baeyer-Villiger oxidations for mixed cyclic ketones.     

Baeyer-Villiger Oxidation of Cyclohexanone with Molecular Oxygen in the Presence of Benzaldehyde

The metal-catalyzed Baeyer-Villiger oxidation of cyclohexanone with molecular oxygen (latm) in the presence of benzaldehyde gives δ -caprolactone in high yield. The same oxidation in the absence of metal catalysts is also studied. Additives to the system can improve the reaction highly efficiently.     

Methods of the synthesis of A-seco derivatives of pentacyclic triterpenoids

The review considers the main methods for the synthesis of derivatives of A-seco pentacyclic triterpenoids by means of the Baeyer-Villiger reaction, the Beckmann rearrangement, and other oxidation processes.