亚洲王米螟性信息素的改良合成

本文报导了亚洲玉米螟性信息素的改良合成. 用1,12-十二碳二醇或10-+-碳烯醇为原料制得溴化(12-羟基十二烷基)三苯基膦, 经强碱作用生成(12-羟基十二烷基)三苯基膦, 与乙醛进行wittig反应后, 得到高顺式的12-十四碳烯醇. 顺式烯醇经异构化得到79%反式烯醇, 从而得到顺式及反式12-十四碳烯醇醋酸酯.     

第五、六族元素的有机化合物在有机合成中应用的研究XXIX, 甲氧羰基亚甲基三苯基膦、胂与2-全氟炔酸甲酯的反应以及3-全氟烷基-戊烯二酸二甲酯的合成

甲氧羟基亚甲基三苯基膦(1a)、胂(1b)与2-金氟炔酸甲酯(2)在无水苯中迅速反应,生成高产率的加合物3. 3的结构通过元素分析、红外光谱、核磁共振谱和质谱予以鉴定,并证明了反应机理. 胂叶立德3d, 3e和3f在温和条件下水解,砷-碳键断裂,合成了高产率的3-全氟烷基-戊烯二酸二甲酯(7)。     

N-(11-羧基十一烷基)马来酰亚胺及其三聚体的合成

以顺丁烯二酸酐和12-氨基十二酸为原料,硫酸、三乙胺为脱水催化剂,经两步反应合成了N-(11-羧基十一烷基)马来酰亚胺.再在三苯基膦和苯酚作用下,N-(11-羧基十一烷基)马来酰亚胺进一步发生三聚反应合成了相应的马来酰亚胺三聚体.采用红外光谱和核磁共振谱对三聚体的结构进行了表征.     

应用不同交联度的聚合物Wittig试剂合成亚洲玉米螟性信息素

我国广东省测试分析中心及美国的Klun几乎同时确定亚洲玉米螟性信息素的化学结构为(E)及(Z)-12-十四碳烯-1-醇乙酸酯(Z:E=1:1)。合成方法大多由合适的炔烃出发,先合成相应的炔键类似物,再转化成烯键,但原料较难获得,反应条件苛刻,路线长或产率     

聚合物支持的三苯基氯硅烷在昆虫性信息素固相合成中的应用

1%二乙烯基苯交联的聚苯乙烯树脂在N,N,N',N'-四甲基乙二胺的存在下用丁基锂进行锂化后与二苯基二氯硅烷反应制得聚苯乙烯支持的三苯基氯硅烷(2).这种聚合物用于一些鳞翅目(lepidoptera)昆虫的性信息素的固相合成.2与1,9-壬二醇,1,10-癸二醇和1,12-十二碳二醇反应分别生成聚合物支持的二醇单硅醚(4a,4b,4c),游离的醇基用Swern试剂(DMSO和草酸酰氯)氧化成聚合物支持的醛(5a,5b,5c),经Wittig缩合反应和用氟离子裂解后分别得到9-十四碳烯醇-1(8a),10-十四碳烯醇-1(8b)和12-十四碳烯醇-1(8c).化合物8经乙酰化后分别得到9-十四碳烯醇-1乙酸酯(9a),其顺式异构体是秋灰夜蛾(S.frugiperda,Smith)的性信息素;10-十四碳烯醇-1乙酸酯(9b),其顺式异构体是橡卷叶蛾(A.semiferamus,Walker)的性信息素;和12-十四碳烯醇-1乙酸酯(9C).9C与四氯化碲反应,硫化钠还原后转化成E-和Z-异构体比例为54:46的亚洲玉米螟(Ostriniafurnicalis)的性信息素.     

Morita-Baylis-Hillman型[3,3]-σ重排实现的Z选择性α-芳基化反应

[3,3]-重排反应是形成碳碳键的重要反应,近年来,芳基亚砜与特定亲核试剂(烯丙基/炔丙基硅烷、内炔烃、羰基化合物、酚、锡基腈以及烷基腈等)参与的[3,3]-重排反应引起了合成化学家的广泛关注[4].其中,浙江师范大学化学与生命科学学院彭勃课题组提出“组装-脱质子”的重排策略,先后实现了芳基亚砜与烷基腈[5]、烯丙基腈...     

Au(Ⅰ)配合物催化剂室温高效催化炔烃水合反应

合成了一系列(1,1'-联苯)-2-二(1-金刚烷基)磷配体,并制备出8种相应的Au(Ⅰ)配合物.以甲醇为溶剂,在6-十二炔水合反应中考察了8种Au(Ⅰ)配合物的催化性能,结果表明,以含有3'-(吡咯-1-羰基)官能团的Au(Ⅰ)配合物为催化剂时,其用量仅需炔烃用量的0.1%~0.3%(摩尔分数),室温下即可高效地催化炔烃进行水合反应.     

Au(Ⅰ)配合物催化剂室温高效催化炔烃水合反应

合成了一系列(1,1'-联苯)-2-二(1-金刚烷基)磷配体, 并制备出8种相应的Au(Ⅰ)配合物. 以甲醇为溶剂, 在6-十二炔水合反应中考察了8种Au(Ⅰ)配合物的催化性能, 结果表明, 以含有3'-(吡咯-1-羰基)官能团的Au(Ⅰ)配合物为催化剂时, 其用量仅需炔烃用量的0.1%~0.3%(摩尔分数), 室温下即可高效地催化炔烃进行水合反应.     

第五、六族元素的有机化合物在有机合成中应用的研究 ⅩⅩⅠⅩ.甲氧羰基亚甲基三苯基膦、胂与2-全氟炔酸甲酯的反应以及3-全氟烷基-戊烯二酸二甲酯的合成

甲氧羰基亚甲基三苯基膦(1a)、胂(1b)与2-全氟炔酸甲酯(2)在无水苯中迅速反应,生成高产率的加合物3.3的结构通过元素分析、红外光谱、核磁共振谱和质谱予以鉴定,并证明了反应机理.胂叶立德3d,3e和3f在温和条件下水解,砷—碳键断裂,合成了高产率的3-全氟烷基-戊烯二酸二甲酯(7).     

可见光催化炔烃串联氰基烷基磺酰化/环化（英文）

报道了一种在无过渡金属条件下可见光催化炔烃与环酮肟衍生物的串联氰基烷基磺酰化/环化反应,通过SO_2的插入合成2-氰基烷基磺酰基-9H-吡咯并[1,2-a]吲哚.该碳碳叁键的双官能团化包括自由基机理,依次经历了亚胺自由基的形成、环酮的开环、SO_2的插入、磺酰基对碳碳叁键的加成、分子内环化和异构化.     

Synthesis of Some [1,3]Benzodioxoles via the Reaction of o-Quinones with Phosphorus Ylides

3,5-Di(tert-butyl)benzo-1,2-quinone 1c, phenanthrene-9,10-quinone 11, and 1,2-naphthoquinone 18 react with 1-phenylethylidene(tri-phenyl)phosphorane 2j, cyclopentylidene(triphenyl)phosphorane 2k, cyclohexylidene(triphenyl)phosphorane 2l, and tetrahydro-2-furanyl-methylidene(triphenyl)phosphorane 8 to give the corresponding 2-substituted [1,3]benzodioxoles 5–7, 10, 12–14, 20–22 in low to high yields, instead of Wittig products, with exception of 11,12-dihydro-10H-cyclopenta[b]phenanthro[9,10-d]furan 17. A possible explanation for these reaction sequences is discussed.

     

A Convenient Synthesis of 3-Behzyl, 3-Benzyl-4-Substituted Coumarins and Their Benzo Derivatives

It is reported in the literature that alkylation of simple (unsubstituted) phosphorane with alkyl halide in ethyl acetate leads to equimolar mixture of alkylated phosphorane and salt of the unsubstituted phosphorane. Here we report exclusive formation of alkylated phosphorane from its salt from benzyl bromide in chloroform. This alkylated phosphorane (2) on reaction with 2-hydroxy carbony1 compounds (1a-1) provide E-ethyl Oc-benzyl cinnamates in high yields which on thermal cyclisation gave 3-benzylf 3-benzyl-4-substituted and benzocoumarins. Thus this method can be used conveniently to synthesise above compounds in good yields.     

Unsuccessful/successful attempts to produce penta(heteroaryl)-phosphoranes/-arsoranes R5E (E = P, As; R = 2-furyl, 2-thienyl)

Tri(2-thienyl)phosphine (1) has been transformed into chlorotri(2-thienyl)phosphonium chloride (3) in the reaction with hexachloroethane, into tetra(2-thienyl)phosphonium bromide (4) in a NiBr2-catalyzed quaternization with 2-bromothiophene, and into the p-tolylsulfonyliminotri(2-thienyl)phosphorane (6) using "chloramine T". Attempts to generate the homoleptic penta(2-thienyl)phosphorane (2-C4H3S)5P (5) by treating 3, 4, 6 or the known (PhO)3P=NSO2C6H4-2-Me (9) with 2-thienyllithium were unsuccessful. Tri(2-furyl)phosphine (2) was converted into the related imine 7, but the reaction of 7 or of 9 with 2-furyllithium failed to give (2-C4H3O)5P (8). It was only with the strained phosphorane Ph(C12H8)P=NSO2C6H4-4-Me (C12H8= 2,2'-biphenylylene) (10) that with 2-C4H3OLi the corresponding phosphorane Ph(C12H8)P(C4H3O-2)2 (11) could be obtained (31P NMR: delta-106.7 ppm). In the arsenic series, tri(2-thienyl)- and tri(2-furyl)arsine (12, 13) were converted into the tosylimino compounds (14, 15) and successfully transformed into the homoleptic arsoranes with 2-C4H3E-Li: penta(2-thienyl)- (16) and penta(2-furyl)-arsorane (17) are stable colourless crystalline solids, the NMR spectra of which indicate rapid pseudo-rotation in solution. The single crystal structure analysis of 17 shows an only slightly distorted trigonal-bipyramidal configuration. In crystals of the phosphine 2 and the arsine 13 the molecules have a propeller configuration with approximate C3v symmetry for the former, but Cs symmetry for the latter. The crystal structures of the precursors or intermediates 3, 4, 6, 9, and 10 have also been determined.     

Synthesis of 5S,12S - diHETE (LTBx)

The total synthesis of 5S, 12S-diHETE (LTB_x) was completed. The Wittig reaction of phosphorane 8 and chiral aldehyde 9 provided the key step to from the C-20 chain.     

Theoretical studies on the hydrolysis of phosphate diesters in the gas phase,solution, and RNase A

Density functional theory, polarizable continuum models and semiempirical hybrid quantum mechanical/molecular mechanical (QM/MM) calculations were applied to the hydrolysis of phosphate diesters in the gas phase, in solution, and in the enzyme RNase A. Neutralization of the negative charge of the pentacovalent phosphorane intermediates provides a substantial stabilization of the transition‐state structures in the gas phase. Inclusion of solvent effects on the phosphate/phosphorane species was critical to reproducing the trends in reactivity observed experimentally. Finally, the catalytic mechanism for the hydrolysis of uridine 2′,3′‐cyclic phosphate by RNase A was studied by QM/MM calculations. Our results suggest that the rate‐limiting transition state of the reaction corresponds to the approach of a water molecule to the phosphate and its activation by His119. Thus, His119 acts as a generalized base for the reaction. The water attack leads to a pentacovalent phosphorane transition state of formal charge ?2; this excess of negative charge in the transition state is stabilized by a number of positively charged residues including His12 and Lys41. In the second stage of the reaction, the phosphorane is converted into products. This part of the reaction proceeds without a detectable barrier, and it is facilitated by a proton transfer from Lys41 to the departing O_2′. © 2001 John Wiley & Sons, Inc. Int J Quantum Chem, 2001     

Organometallic synthons: The wittig reaction of tricarbonyl [(3,4,5,6-η)-1,3,5-cycloheptatriene-1-carboxaldehyde] iron

The utility of the Wittig reaction in synthesis of organometallic compounds is exemplified by its application to the preparation of a series of tetraene—Fe(CO)₃ complexes from aldehyde 9 and a variety of triphenylphosphoranes. Reaction of 9 with triphenylmethylene phosphorane afforded unexpectedly a $\text{1}\text{1}$ isomeric mixture of 8-methylheptafulveneiron tricarbonyl (12), probably via a (1,9) hydrogen shift of intermediate 11. Triphenylbenzylidene phosphorane condensed with 9 to give the cis and trans isomers of cycloheptatrienyl—styrene complex 14. The triphenylphosphoranes of carbomethoxymethylene, carboethoxymethylene and cyanomethylene react with 9 yielding the appropriate trans condensation products exclusively. Tetracyanoethylene (TCNE) and N-phenyltriazolinedione (NPTD) readily react periselectively with the unrearranged Wittig reaction products at the free diene moiety, affording the corresponding 4+2 cycloadducts. Heptafulvene complex 12, upon reaction with TCNE, gave the 8+2 cycloadduct 26.     

Insertion of chloral into P-Br bond of phosphoranes

Chloral inserts into the P-Br bond of pyrocatechintribromophosphorane with the formation of stable mono-, di- and tri(1-bromo-2,2,2-trichloroethoxy) phosphoranes and, also, into the P-Br bond of bis (pyrocatechin) bromophosphorane with the formation of 1-bromo-2,2,2-trichloroethoxybis (pyrocatechin) phosphorane.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2819–2823, December, 1989.     

New routes to 5,8,5-triphenylbenzo[c]heptafulvenes from (3,4-bis(diphenylmethylene)-2-oxocyclobutylidene)triphenylphosphorane. Isolation of excessively stabilized betaine

Thermal isomerization of HBr salt of the title phosphorane gave (2-hydroxy-5,8,8-triphenylbenzo[c]heptafulvenyl)trphenylphosphonium bromide, which upon dehydrobromination afforded excessively stabilized betaine. Thermal reaction of the title phosphorane with diphenylketene gave 5,8,8-triphenyl-benzo[c]heptafulvene which is condensed with cyclopropene ring.     

Synthesis of 6-substituted pyrimidines by the wittig reaction. I. Via 2-amino-4-hydroxy-5-phenylbutylpyrimidine-6-carboxaldehyde

Condensation of isopropyl 6-phenylhexanoate with ethyl diethoxyacetate followed by guanidine afforded 2 - amino-6-diethoxymethyl-5-phenylbutyl-4-pyrimidinol (VII). Acid hydrolysis of VII gave an excellent yield of 2-amino-4-hydroxy-5-phenylbutylpyrimidine-6-carboxaldehyde (IV); the latter could be condensed with stabilized Wittig reagents such as carbethoxymethylene triphenyl phosphorane and cinnamylidene triphenyl phosphorane, but not unstabilized Wittig reagents such as carbethoxypropylene or cyano-propylene triphenyl phosphorane. Reduction of the Wittig products afforded pyrimidines with functionalized side-chains in the 6-position such as the 6-phenylbutyl (XVIII) and 6-carboxyethyl (XV) derivatives of 2-amino-5-phenylbutyl-4-pyrimidinol.     

Modified and environmentally friendly oxidation of phosphorane ylides to vicinal tricarbonyls using unsupported moist Oxone in dichloromethane

Abstract

Modified and eco-friendly oxidation of phosphorane ylides to the corresponding vicinal tricarbonyls (VTC) using unsupported moist Oxone in dichloromethane at room temperature is described. This green oxidation protocol is simple, mild, and highly efficient to operate, and allowing a chemoselective preparation of VTC from various phosphorane ylides without tedious workup procedures of extraction/drying process in excellent yields.