两相催化体系中α，β－不饱和醛的选择性加氢反应研究Ⅰ．水溶性钌－膦配合物催化肉桂醛的加氢性能

本文研究了两种水溶性钌－膦配合物ＲｕＣｌ_２（ＴＰＰＴＳ）_３和Ｒｕｃｌ_２（ＣＯ）_２（ＴＰＰＴＳ）_２［ＴＰＰＴＳ为：Ｐ（ｍ－Ｃ_６Ｈ_４ＳＯ_３Ｎａ）_３］的合成，在水相和有机相组成的两相催化体系中，考察了它们衍生出的活性物种和以ＲｕＣｌ３－ＴＰＰＴＳ原位合成的活性物种对肉桂醛的选择加氢性能，并对反应温度（２０—８０℃），氢压（２—６ＭＰａ），催化剂浓度（１．１２×１０~（－３）～４．５０×１０~（－３）ｍｏｌ／Ｌ），配体ＴＰＰＴＳ浓度（９．０×１０~（－３）～５．４×１０~（－２）ｍｏｌ／Ｌ），表面活性剂浓度和反应时间的变化对选择加氢反应的影响进行了详细研究。实验结果表明，ＲｕＣｌ_３－ＴＰＰＴＳ原位合成配合物的催化加氢活性最高，而在金属Ｒｕ上羰基的配位将使加氢活性降低，表面活性剂ＣＴＡＢ是有效的促进剂，它的加入可大大提高加氢活性，选择适当的ＣＴＡＢ浓度，在反应结束后水相与有机相分层迅速，有利于Ｒｕ催化剂的分离，在所考察的反应条件下，肉桂醛选择加氢生成肉桂醇的转化率大于８０％，选择性达９６％以上。     

两相体系中钌膦配合物催化4—苯基—3—丁烯—2—酮加氢反应的研究

研究了水和有机物组成的两相催化体系中,由ＲｕＣｌ３－ＴＰＰＴＳ（ＴＰＰＴＳ：Ｐ（ｍ－Ｃ６Ｈ４ＳＯ３Ｎａ）３）原位反应生成的催化活性物种对４－苯基－３－丁烯－２－酮（又名苄叉丙酮）的催化加氢反应．考察了钌浓度（１．０×１０－３～６．０×１０－３ｍｏｌ／Ｌ）、氢压（１．０～６．０ＭＰａ）、反应温度（３０～７０℃）、配体浓度（１．２～７．２×１０－２ｍｏｌ／Ｌ）、阳离子表面活性剂（ＣＴＡＢ：十六烷基三甲基溴化铵）及反应时间等对加氢反应活性和选择性的影响,并与以配合物ＲｕＣｌ２（ＴＰＰＴＳ）３为催化剂前体生成的催化活性物种对加氢反应的活性及选择性进行了比较．结果表明,分别由配合物ＲｕＣｌ２（ＴＰＰＴＳ）３及ＲｕＣｌ３－ＴＰＰＴＳ原位反应生成的催化活性物种,都只催化４－苯基－３－丁烯－２－酮的Ｃ＝Ｃ键选择加氢．由配合物ＲｕＣｌ２（ＴＰＰＴＳ）３形成的催化体系的加氢活性及选择性均优于ＲｕＣｌ３－ＴＰＰＴＳ原位反应生成的催化活性物种．阳离子表面活性剂的加入,使加氢反应活性下降,选择性略有提高     

水溶性钯－膦配合物催化1－己烯加氢反应研究

研究了水溶性钯－膦配合物ＰｄＣｌ２（ＴＰＰＴＳ）２催化１－己烯加氢反应，考察了两相催化体系中添加表面活性剂ＣＴＡＢ，膦配体ＴＰＰＴＳ，以及溶液ｐＨ值等对反应的影响，证明了１－己烯加氢反应中有一诱导期．反应中涉及两种催化活性物种．一种是由ＰｄＣｌ２（ＴＰＰＴＳ）２还原生成的低氧化态催化物种，它在一定的ＣＴＡＢ浓度下，可以保持相当的稳定性．另一种是被ＴＰＰＴＳ或Ｈ２还原形成的钯黑．根据ＰｄＣｌ２和ＴＰＰＴＳ反应过程的３１ＰＮＭＲ研究，对ＰｄＣｌ２（ＴＰＰＴＳ）２分子中Ｐｄ被还原和ＴＰＰＴＳ被氧化提出了解释     

水溶性钯—膦配合物催化1—己烯加氢反应研究

研究了水溶性钯－膦配合物ＰｄＣｌ２（ＴＰＰＴＳ）２催化１－己烯加氢反应，考察了两相催化体系中添加表面活性剂ＣＴＡＢ，膦配体ＴＰＰＴＳ，以及溶液ＰＨ值等对反应的影响。证明了１－己烯加氢反应中有一诱导期。反应中涉及两种催化活性物种。     

水溶性钯配合物催化柠檬醛的选择加氢研究 Ⅱ.催化剂的循环使用

研究了以水溶性ＰｄＣｌ２（ＴＰＰＴＳ）２为催化剂，在水／有机物两相体系中，添加ＴＰＰＴＳ、ＣＴＡＢ、ＰＶＡ、明胶和碳酸钠对柠檬醛加氢反应及催化剂稳定性的影响．添加配体ＴＰＰＴＳ、明胶或表面活性剂ＣＴＡＢ有利于减少钯黑的形成，但会引起催化活性的降低；而添加ＰＶＡ和Ｎａ２ＣＯ３，虽然都不能抑制钯黑的形成，但后者的添加会明显提高加氢速度；发现，明胶加碳酸钠的体系不仅可以稳定催化剂的活性物种，避免钯黑的析出，而且催化反应的转化率及选择性都较高．     

水溶性铑－膦配合物的结构及性能表征

采用ＩＣＰ、ＦＴＩＲ、１３ＣＷＲ、３１ＰＮＭＲ、ＴＧＡ、ＸＰＳ等方法，对三种水溶性铑配合物：ＨＲｈ（ＣＯ）（ＴＰＰＴＳ）３、ＲｈＣｌ（ＣＯ）（ＴＰＰＴＳ）２和ＲｈＩ（ＣＯ）（ＴＰＰＴＳ）２的组成、结构和性质进行了表征．结果表明，采用新设计的方法合成的水溶性铑－膦配合物，具有以三苯基膦为配体的配合物类似的结构．它们的热稳定性很好，在水中的溶解度大，而在非极性有机溶剂中极难溶解，是良好的烯烃氢甲酰化催化剂．     

Carbonylation of Allyl Chloride Catalyzed by PdCl_2（TPPTS）_2 in Two－phase Medium

ＣａｒｂｏｎｙｌａｔｉｏｎｏｆＡｌｌｙｌＣｈｌｏｒｉｄｅＣａｔａｌｙｚｅｄｂｙＰｄＣｌ_２（ＴＰＰＴＳ）_２ｉｎＴｗｏ－ｐｈａｓｅＭｅｄｉｕｍＣａｒｂｏｎｙｌａｔｉｏｎｏｆＡｌｌｙｌＣｈｌｏｒｉｄｅＣａｔａｌｙｚｅｄｂｙＰｄＣｌ_２（ＴＰＰＴＳ）_２ｉｎ...     

La(ClO4)3-OCBAAP-H2O体系(30℃)溶度及Ln(OCBAAP)4(ClO4)3·nH2O的合成和表征

测定了三元体系Ｌａ（ＣｌＯ４）３－ＯＣＢＡＡＰ－Ｈ２Ｏ在３０℃时的溶解度．结果表明，该体系有一个新固相（不一致溶解化合物）Ｌａ（ＯＣＢＡＡＰ）４（ＣｌＯ４）３·６Ｈ２Ｏ形成．参考该体系溶度图确定合成条件，合成了系列化合物Ｌｎ（ＯＣＢＡＡＰ）４（ＣｌＯ４）３·ｎＨ２Ｏ（Ｌｎ＝Ｌａ，ｎ＝６；Ｌｎ＝Ｐｒ，Ｎｄ，Ｓｍ，Ｇｄ，Ｙｂ，ｎ＝２）．通过化学分析、元素分析、ＴＧ－ＤＴＧ、ＩＲ和密度对化合物进行了表征，计算了Ｌａ（ＯＣＢＡＡＰ）４（ＣｌＯ４）３热分解过程各阶段的表观活化能．     

水溶性铑—膦配合物催化长链烯烃氢甲酰化反应研究—反应条件的影响

本文研究了两相催化体系中，在ＣＴＡＢ（Ｃ１６Ｈ３３ＮＭｅ３Ｂｒ）存在下，水溶性铑－膦配合物ＲｈＣｌ（ＣＯ）（ＴＰＰＴＳ）２对１－己烯氢甲酰化反应的催化性能，详细考察了反应温度、压力、膦／铑比等对催化活性的影响。结果表明，在１．０ＭＰａ恒压下，反应温度１００℃，膦／铑摩尔比为１６，Ｈ２：ＣＯ＝１：１的条件下，１－己烯氢甲酰化的转化频率（ＴＯＦ）可达到３９．８ｍｉｎ＾－１。在此反应条件下，有机相和水相     

烯丙基硫脲与支持电解质阴离子在银电极上共吸附的拉曼光谱

用表面增强拉曼散射光谱（ＳＥＲＳ）和时间分辨ＳＥＲＳ光谱（ＴＲＳＥＲＳ）等技术首次研究了烯丙基硫脲（ＡＴＵ）在ＨＣｌＯ４、Ｈ２ＳＯ４和ＨＮＯ３介质中与无机阴离子在银电极上的电化学共吸附行为．提出ＡＴＵ很可能以Ｓ端与银电极表面形成化学吸附键，仲氨基相对伯氨基距离表面较近，整个分子偏向烯丙基一侧倾斜吸附在表面上．ＣｌＯ－４、ＳＯ２－４和ＮＯ－３等弱吸附无机阴离子均能被ＡＴＵ诱导共吸附在其质子化了的仲氨基上，这３种无机阴离子被ＡＴＵ诱导共吸附的强弱顺序是ＣｌＯ－４＞ＳＯ２－４＞ＮＯ－３．被诱导共吸附的无机阴离子对ＡＴＵ在电极表面的化学吸附起到稳定剂的作用，有利于ＡＴＵ在电极表面形成致密的吸附层     

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.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

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.     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

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.