乙烯基锡修饰的双吡唑甲烷第六族金属羰基化合物的合成与反应

通过双吡唑基甲基锂与二苯基乙烯基碘化锡的反应, 合成了桥头碳上带有乙烯基锡修饰的双吡唑甲烷配体。在回流的THF中这些乙烯基锡修饰的双吡唑甲烷配体(R3SnCHPz2, R3Sn为三乙烯基锡或二苯基乙烯基锡;Pz代表取代吡唑)与M(CO)5THF (M = Mo或W)反应产生杂双金属化合物R3SnCHPz2M(CO)3。在这些化合物中,一个乙烯基以h2方式配位到金属钼或钨上,双吡唑甲烷表现为一个三齿k3-(p,N,N)配体。(CH2=CH)3SnCH(3,5-Me2Pz)2W(CO)3和Ph2(CH2=CH)SnCH(3,5-Me2Pz)2W(CO)3与I2的反应也被研究。前者给出化合物CH2(3,5-Me2Pz)2W(CO)4,而后者随着有机锡的丢失产生四元金属杂环化合物CH(3,5-Me2Pz)2W(CO)3I。用PhSNa处理该四元金属杂环化合物导致碘负离子被取代,得到化合物CH(3,5-Me2Pz)2W(CO)3SPh。     

桥头碳上氮杂芳基功能化的双吡唑甲烷与羰基钨反应（英文）

研究了(氮甲基咪唑-2-基)双(3,5-二甲基吡唑)甲烷(L1),2-吡啶基双(3,5-二甲基吡唑)甲烷(L2)及4-吡啶基双(3,5-二甲基吡唑)甲烷(L3)与羰基钨的反应,合成了一系列以单齿,双齿及三齿氮配位的羰基金属衍生物LW(CO)5(L=L1或L3),LW(CO)4(L=L1,L2或L3)和LW(CO)3(L=L1或L2)。核磁,红外及X-射线单晶衍射分析表明这3种配体表现出了可变的配位方式。在LW(CO)5中,当配体为L1时,其倾向于通过咪唑氮与金属配位,而为L3则倾向于利用吡啶氮与金属作用;在LW(CO)4中,配体L1表现为通过咪唑氮和吡唑氮原子配位的[N,N′]双齿配体,而L2和L3表现为通过吡唑氮原子配位的[N,N]双齿配体;在LW(CO)3中,L1和L2起着[N,N,N′]三齿螯合配体的作用。     

桥头碳上氮杂芳基功能化的双吡唑甲烷与羰基钨反应

研究了(氮甲基咪唑-2-基)双(3,5-二甲基吡唑)甲烷(L1),2-吡啶基双(3,5-二甲基吡唑)甲烷(L2)及4-吡啶基双(3,5-二甲基吡唑)甲烷(L3)与羰基钨的反应,合成了一系列以单齿,双齿及三齿氮配位的羰基金属衍生物LW(CO)5(L=L1或L3),LW(CO)4(L=L1,L2或L3)和LW(CO)3(L=L1或L2)。核磁,红外及X-射线单晶衍射分析表明这3种配体表现出了可变的配位方式。在LW(CO)5中,当配体为L1时,其倾向于通过咪唑氮与金属配位,而为L3则倾向于利用吡啶氮与金属作用;在LW(CO)4中,配体L1表现为通过咪唑氮和吡唑氮原子配位的[N,N′]双齿配体,而L2和L3表现为通过吡唑氮原子配位的[N,N]双齿配体;在LW(CO)3中,L1和L2起着[N,N,N′]三齿螯合配体的作用。     

以2-(1-吡唑基甲基)吡啶类化合物为配体的羰基钼、钨衍生物的合成及结构

合成了2-[1-(3-叔丁基)吡唑基甲基]吡啶(CH2(Py)(3-ButPz)),并研究了羰基钼(钨)与该配体及其类似物2-(1-吡唑基甲基)吡啶(CH2(Py)(Pz))和2-[1-(3,5-二甲基)吡唑基甲基]吡啶(CH2(Py)(3,5-Me2Pz))的反应,合成了6个含双齿螯合的2-(1-吡唑基甲基)吡啶类配体的四羰基金属衍生物CH2(Py)(3-ButPz)M(CO)4,CH2(Py)(Pz)M(CO)4和CH2(Py)(3,5-Me2Pz)M(CO)4(M=Mo或W)。当用SnCl4处理CH2(Py)(3,5-Me2Pz)M(CO)4时,Sn-Cl键对金属中心发生氧化加成得到2个杂双核金属有机化合物CH2(Py)(3,5-Me2Pz)M(CO)3(Cl)SnCl3。所有新化合物均通过了红外和核磁的表征,CH2(Py)(3-ButPz)W(CO)4和CH2(Py)(3,5-Me2Pz)W(CO)3(Cl)SnCl3的结构还得到了X-射线单晶衍射的确证。用循环伏安法测定了四羰基金属衍生物的电化学性质。     

桥头碳上氮杂芳基功能化的双吡唑甲烷与羰基钨反应

研究了(氮甲基咪唑-2-基)双(3,5-二甲基吡唑)甲烷(L¹),2-吡啶基双(3,5-二甲基吡唑)甲烷(L²)及4-吡啶基双(3,5-二甲基吡唑)甲烷(L³)与羰基钨的反应,合成了一系列以单齿,双齿及三齿氮配位的羰基金属衍生物LW(CO)₅ (L=L¹或L³),LW(CO)₄ (L=L¹,L²或L³)和LW(CO)₃ (L=L¹或L²).核磁,红外及X-射线单晶衍射分析表明这3种配体表现出了可变的配位方式.在LW(CO)₅中,当配体为L¹时,其倾向于通过咪唑氮与金属配位,而为L³则倾向于利用吡啶氮与金属作用;在LW(CO)₄中,配体L¹表现为通过咪唑氮和吡唑氮原子配位的[N,N']双齿配体,而L²和L³表现为通过吡唑氮原子配位的[N,N]双齿配体;在LW(CO)₃中,L¹和L²起着[N,N,N']三齿螯合配体的作用.     

基于2,5-二甲基苯-1,4-二亚甲基二膦酸的钴、镍同构化合物的水热合成及晶体结构(英文)

在水热条件下,利用2,5-二甲基苯-1,4-二亚甲基二膦酸(H4L)与CoCl2·6H2O或NiSO4·6H2O反应得到2个同构的过渡金属有机膦酸化合物,[Co(H2O)4(H2L)]n(1),[Ni(H2O)4(H2L)]n(2),并用元素分析、红外光谱、粉末及单晶X-射线等方法对其进行了表征。晶体结构分析表明:化合物1和2都属于三斜晶系,空间群为P1,化合物1的晶胞参数为a=0.497 0(2)nm,b=0.711 3(3)nm,c=1.177 8(5)nm,α=97.779(7)°,β=92.103(7)°,γ=107.217(6)°,V=0.3927(3)nm3,Z=2;化合物2的晶胞参数为a=0.494 35(19)nm,b=0.708 9(3)nm,c=1.172 6(5)nm,α=97.919(6)°,β=92.130(6)°,γ=107.441(5)°,V=0.387 0(3)nm3,Z=2。金属离子采取了八面体构型,6个配位氧原子分别来自2个反式构型的H2L配体和4个配位水分子。每1个金属离子与2个反式构型的H2L配体配位形成了一维线型链状结构。这2个化合物最终通过O-H…O氢键作用形成了三维结构。此外,对2个化合物的热稳定性也进行了研究。     

含钼(钨)锡键的四元金属有机杂环化合物的合成与反应研究

通过三苯基锡基-双(3,5-二甲基吡唑)甲烷与羰基钼的反应合成了钼锡键合的四元金属杂环化合物CH(3,5- Me₂Pz)₂Mo(CO)₃SnPh₃ (Pz＝1-吡唑基). 当用叔丁基异腈处理该化合物及其钨类似物时, 伴随着有机锡结构单元的丢失, 金属钼(钨)上发生还原消除并分解得到化合物CH₂(3,5-Me₂Pz)₂M(CO)₃(CNBu-t) (M为Mo或W). 另外, 该化合物与三苯基膦或亚磷酸甲酯及异丙酯反应时, 只发生羰基取代反应得到化合物CH(3,5-Me₂Pz)₂Mo(CO)₂(PR₃)SnPh₃ (R为苯基、甲氧基及异丙氧基). 而用亚磷酸苯酯与之反应, 除得到羰基取代产物外, 还伴随着P-O/C键的交换, 得到金属钼上还原消除的产物(PhO)₂PCH(3,5-Me₂Pz)₂Mo(CO)₃.     

由氢键连接的三个金属-有机网状化合物的合成、结构及半导体性质（英文）

以2,4,6-三(1-吡唑基)-1,3,5-三嗪(TPTz)与不同金属离子进行溶剂热反应,得到了3个氢键连接的金属-有机网状化合物。实验发现TPTz的水解产物6-(1-吡唑基)-1,3,5-三嗪-2,4-二酚(H_2L)在反应中起到了实际的配位作用。单晶结构分析表明,它们是同构化合物,分子式为[M(HL)_2]·2H_2O(M=Zn,1;Co,2;Mn,3)。每个中心金属原子分别与2个吡唑基上的N、2个吡嗪环上的N和2个水分子中的O形成六配位的结构。2个HL与1个中心金属配位形成一个零维的金属一有机配合物小分子,这些小分子通过氢键连接进一步拓展为二维层状结构。紫外一可见漫反射(UV-Vis DRS)分析结果表明,这3种化合物都是宽系半导体材料,其带隙宽度分別为3.80(Zn),3.30(Co),3.27(Mn)eV,其半导体性质同中心金属原子表现出明显的相关性。     

双(3,5-二甲基-4-苄基吡唑)甲烷ⅥB族羰基化合物的合成及反应

通过 3 ,5 -二甲基 -4-苄基吡唑与二溴甲烷在相转移催化下反应 ,合成了一个新的多吡唑烷配体双 (3 ,5 -二甲基 -4-苄基吡唑 )甲烷 .该配体与 M(CO) 6 (M=Cr,Mo,W)在光照下反应可以得到双 (3 ,5 -二甲基 -4-苄基吡唑 )甲烷四羰基铬 (2 )、钼 (3 )和钨 (4 ) .用 Sn Cl4 处理化合物 3和 4可以高产率地制得含 Mo(W)— Sn键的杂双金属配合物 .用 X射线衍射法测定了化合物 4与 Sn Cl4 反应产物 6的晶体结构 .结果表明 ,该晶体属三斜晶系 ,P1空间群 ,晶胞参数 a=1 .0 92 9(9) nm,b=1 .2 82 (1 ) nm,c=1 .2 82 (1 ) nm,α=1 0 2 .3 5 (1 )°,β=1 0 8.62 (1 )°,γ=97.0 0 (1 )°,V=1 .799(3 ) nm3,Z=2 ,最终结构偏离因子 R=0 .0 5 8,w R=0 .1 0 1 5 ,GOF=0 .90 5 .六元金属杂环 W— N— N— C— N— N为船式构象 ,分子中没有氯桥存在 .     

双核钼/钨金属键有机化合物的反应化学研究

着重总结了我们研究组近几年来对M-M(M=Mo,W)金属单键化合物(η^5-RC5H4)2M2(CO)6,M=M金属双键化合物(η^5-RC5H4)2M2(CO)2(μ-EPh)2(E=S,Se,Te)及M≡M金属三键化合物(η^5-RC5H4)2M2(CO)4的反应化学所取得的系列成果。该系列成果清楚地表明这三类典型的金属键有机化合物可分别同多种无机、有机以及金属有机试剂发生涉及金属键加成、金属键断裂以及金属键上配体的消除和环戊二烯基配体上有机官能团的转化等一系列有趣反应。这些反应不仅有重要理论意义而且被广泛地用在新型金属有机和原子簇化合物的合成上。     

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%).     

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.     

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.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

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.