新型手性β—氨基醇用于不对称催化醛类烷基化反应

将自己研制的一种新型β－氨基醇作为手性源用于醛类的不对称催化烷基化反应。考察了在这种手性β－氨基醇存在时各种醛和二乙基锌作用生成相应的手性仲醇的光学收率，考察了几种反应条件参数对于苯甲醛的这种不对称催化反应的影响，其中最佳结果为１－苯基丙醇的光学收率达７４．１％，而其化学产率达９３．８％。     

新型手性氨基醇的合成及其用于不对称催化醛类烷基化反应

制备了一种由糖类化合物衍生的新型手性氨基醇（Ⅰ），并将其作为手性源用于醛类的不对称烷基化反应．考察了在手性氨基醇的存在下，各种醛和二乙基锌作用生成相应的手性仲醇的光学收率及化学收率．结果表明，该催化剂对于芳香醛的烷基化更为有效．并考察了几种反应条件对于苯甲醛的不对称催化烷基化反应的影响，其中最佳结果为１－苯基－１－丙醇的光学收率达８２．７％，而化学收率达５８．８％．     

新型手性基醇的合成及其用于不对称催化醛类烷基化反应

制备了一种由糖类化合物衍生物新型手性氨基醇（Ｉ），并将其作为手性源用于醛类的不对称烷基化反应，考察了在手性氨基酸的存在下，各种醛和二乙基锌作用生成相应的手性仲醇的光学收率及化学收率，结果表明，该催化剂地于芳香醛的烷基化更为有效，并考察了几种反应条件对于苯甲醛的不对称催化烷基化反应的影响，其中最佳结果为１－苯基－１－两醇的光学收率达８２．７％，而化学收率达５８．８％。     

(R)-α-萜品醇的不对称合成

在催化量的手性催化剂存在下，利用１－苯磺酰基－３－丁烯－２－酮与异戊二烯的不对称催化Ｄｉｅｌｓ－Ａｌｄｅｒ反应，合成了（Ｒ）－α－萜品醇５，光学纯度值达到９２％．     

（R）—α—萜品醇的不对称合成

在催化量的手性催化剂存在下，利用１－苯磺酰基－３－丁烯－２－酮与异戊二烯的不对称催化Ｄｉｅｌｓ－Ａｌｄｅｒ反应，合成了（Ｒ）－α－萜品醇５，光学纯度值达到９２％。     

钯-手性膦催化降冰片烯的不对称氢酯基化反应

首次用Ｐｄ（ＯＡｃ）２－１，４∶３，６－双脱水－２，５－二（二苯基膦）－Ｌ－艾杜糖醇（ＤＤＰＰＩ）－ｐ－ＴｓＯＨ催化体系对降冰片烯进行了不对称氢酯基化反应，获得了较好的结果．考察了手性膦配体的结构以及磷原子与钯原子的摩尔比对反应的影响，发现在一个磷原子配位一个钯原子时，获得了较高的光学产率．同时考察了反应温度、反应压力及溶剂对降冰片烯不对称氢酯基化反应的影响，发现在１２０℃，５．０ＭＰａ，ｎ（Ｐ）／ｎ（Ｐｄ）＝１时，化学产率可达７１．６％，光学产率可达９２．２％．     

光学活性有机钛试剂与苯甲醛不对称加成反应

光学活性二醇（１Ｒ，２Ｒ）－（＋）－１，２－二苯基－１，２－乙二醇（Ⅲａ）和（２Ｒ，３Ｒ）－（－）－１，１，４，４－四苯基－２，３－（缩丙酮）－１，４－丁二醇（Ⅲｂ）分别修饰Ｔｉ（ＯＰｒｉ）３Ｃｌ，再与甲基锂和乙基锂进行烷基化，制备出新的手性有机钛试剂Ⅱａ和Ⅱｂ，然后与苯甲醛进行加成，所得１－苯基乙醇（Ⅳａ）和１－苯基丙醇（Ⅳｂ）的光学收率分别为２５～６５％ｅ．ｅ．和１０～２０％ｅ．ｅ．。简单讨论了Ｃ２－对称型二醇对立体选择性及反应条件的影响     

手性助剂诱导下的α,β-不饱和酮的不对称加氢反应及其在合成(R)-麝香酮中的应用

在ＴＨＦ溶液中，４０－６０℃及０．３－０．５ＭＰａ氢压条件下，［ＲｕＣｌ２（ｃｈｔ）］２＋（Ｓ）－ＢＩＮＡＰ手性催化剂体系催化不饱和手性缩酮２选择加氢，再经脱去手性二醇，即可高立体选择性地制得（Ｒ）－３－甲基环十五烷酮（４，（Ｒ）－（－）－麝香酮），化学收率≥９５％，光学纯度≥９７％．手性缩酮２由Ｄ－苏糖醇或Ｄ－葡萄糖衍生的手性二醇３与３－甲基环十五烯－２－酮１生成．     

手性Schiff Base—Ti（OR）4配合物催化醛的不对称硅腈化反应

设计合成了新型手性Ｓａｌｅｎ－Ｔｉ（ＯＲ）配合物催化剂，用其催化一系列醛的不同对称硅化反应，得到了ｅ，ｅ值为２２．４％～８７．１％的氰醇，催化剂中抗衡离子的Ｌｅｗｉｓ碱强烈地影响催化活性，但对反应的对映选择性影响很小，并探讨了其不对称催化反应机理。     

（3S）—β—羟基丁酸的合成

以光学活性Ｌ－乳酸为原料，经还原得（２Ｓ）－１，２－丙二醇（２），再经亚硫酰环化、亲核加成及酸解反应，得到手性合成子（３Ｓ）－β－羟基丁酸，收率５８．４％（以的２计），光学纯度大于９０％。     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.     

Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

A variety of N-aryl and N-alkyl carbazolones were conveniently achieved in good to high yields via Pd₂(dba)₃-mediated intramolecular coupling of N-substituted α-iodo enaminones under microwave irradiation. The Pd(0)-catalyzed cyclization was found to proceed favorably with the more electron-deficient phenyl ring during the reactions involving unsymmetrical N,N-diaryl α-iodo enaminones. This unique property enables the construction of carbazolone skeleton containing nitro substituted benzenoid ring.     

Synthesis of substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles by intramolecular nitrilimine cycloaddition

Both substituted 2,4,5,6-tetrahydrocyclopenta[c]pyrazoles and 2,4,5,6-tetrahydropyrrolo[3,4-c]pyrazoles have been synthesized by the 3+2 intramolecular dipolar cycloaddition of nitrilimines to alkynes. This cyclization has been extended to more versatile 3-bromo derivatives by the use of alkynylbromides as dipolarophiles.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Catalyst free,visible-light promoted photoaddition reactions between C60 and N-trimethylsilylmethyl-substituted tertiary amines for synthesis of aminomethyl-1,2-dihydrofullerenes

An efficient and benign method for the preparation of aminomethyl-substituted fullerenes has been developed. The process, involving catalyst free, visible-light irradiation of 10% EtOH-toluene solutions containing fullerene C₆₀ and N-trimethylsilylmethyl-substituted amines by using a 20 W compact fluorescent lamp, leads to formation of aminomethyl-substituted fullerene adducts in a highly efficient manner. The photoaddition reaction takes place via a pathway initiated by visible light absorption by C₆₀, followed by SET from the amine to the triplet excited state of C₆₀. Ethanol-promoted desilylation of the resulting a minimum radical then generates the corresponding α-amino radical which couples with the C₆₀ radical anion to form the anion precursor of the fullerene adducts. The new approach using visible-light takes place under mild conditions and it does not require the use of photocatalysts. Thus, the method developed in this effort could broadens the range of functionalized fullerene derivatives that can be readily prepared.     

Highly efficient and stereoselective cycloaddition of nitrones to indolyl- and pyrrolylacrylates

The reactions of various nitrones with indolyl- and pyrrolylacrylates proceeds regioselectively with high diastereoselectivity in the case of aldonitrones, and represents an effective method for obtaining new indolyl- and pyrrolyl-substituted isoxazolidine carboxylates stabilized by weak (CH?O) and moderate (NH?N) strength intramolecular hydrogen bonding. The resulting cycloadducts exhibit promising in vitro anti-influenza activities.     

Transition metal-free direct amination of benzoxazoles using formamides as nitrogen sources

A transition metal-free method for the direct amination of benzoxazoles using formamides as nitrogen sources is reported, which was mediated by an inexpensive and environmentally friendly tetrabutylammonium iodide/tert-butyl hydroperoxide system and gave the 2-aminobenzoxazole derivatives with moderate to good yields.     

l-Proline-catalyzed five-component domino reaction leading to multifunctionalized 1,2,3,4-tetrahydropyridines

Multifunctionalized 1,2,3,4-tetrahydropyridines are concisely synthesized in good yields via l-proline-catalyzed or l-proline/FeCl₃-cocatalyzed one-pot multicomponent reactions (MCRs). The MCRs involve a domino hydroamination/prins reaction/Mannich-type reaction/intramolecular dehydration-cyclization process. The molecular structure of 5baa, one of multifunctionalized 1,2,3,4-tetrahydropyridines, was confirmed by single-crystal X-ray diffraction.