5-甲基-[(2E,6E)-3,7,11-三甲基-9-氧代十二碳二烯]苯醌和氢醌的首次全合成

以2-甲基对苯二酚和香叶基溴为起始原料, 经过酚羟基保护, 溴代, Li₂CuCl₄催化的芳基溴与Grignard试剂的偶联以及Julia偶联等一系列反应, 完成了裸鳃亚动物的代谢产物, 5-甲基-[(2E,6E)-3,7,11-三甲基-9-氧代十二碳二烯]苯醌(1)和氢醌(2)的首次全合成, 将1用NaBH₄还原, 得到(±)-3, (±)-3也是此类天然产物之一.     

溶剂对钯催化的叔丁基乙炔低聚反应化学选择性的调控作用

报道了溶剂对钯催化的叔丁基乙炔低聚反应化学选择性的调控作用. 反应可在苯-正丁醇双组分溶剂体系中顺利进行, 当双组分溶剂体系中苯占优势比例时, 反应发生递次的三分子炔烃顺式插入, 经由顺式s-烯钯中间体生成环三聚产物1,3,5-三叔丁基苯; 而当双组分溶剂中正丁醇组分上升至一定比例, 反应选择性生成(3Z,5Z)-2,2,7,7-四甲基- 3,6-二氯-3,5-辛二烯或(3Z,5Z)-2,2,7,7-四甲基-3,6-二溴-3,5-辛二烯, 这是由于正丁醇可显著加快C—Pd σ键的断裂, 并与叔丁基乙炔、σ-烯钯中间体形成弱氢键作用力, 同时也与Pd(II)和Cu(II)等离子存在配位效应. 在强极性质子溶剂H₂O中, 反应生成偶联双炔: 2,2,7,7-四甲基-3,5-辛二炔. 文中就反应溶剂体系、钯铜催化剂及反应可能机理等分别进行了探讨.     

松毛虫性信息素前体(4Z,6E)-十一碳二烯醛的合成

从简单原料乙炔出发, 通过炔对丙烯醛的加成得到7-溴代-(4Z,6E)-庚二烯醛, 经乙二醇保护、Pd催化偶联、水解等步骤立体选择性地得到松毛虫性信息素前体(4Z,6E)-十一碳二烯醛.     

NaHSO4•SiO2催化合成β-烯胺酮(酯)

NaHSO₄•SiO₂作催化剂, 1,3-二羰基化合物和伯胺在室温下反应合成了一系列β-烯胺酮(酯), 该法反应条件温和, 产率高, 催化剂能回收再利用.     

手性3,5-二甲基-2-芳基-2-吗啉醇盐酸盐的合成及其晶体结构

以(S)-2-氨基丙醇为手性源与α-溴-3-氯苯丙酮反应, (R)-2-氨基丙醇为手性源与6-甲氧基-2-(2-溴丙酰基)萘反应, 分别合成了手性纯化合物(2R,3R,5S)-3,5-二甲基-2-(3-氯苯基)-2-吗啉醇盐酸盐(4a)和(2S,3S,5R)-3,5-二甲基-2-(6-甲氧基-2-萘基)-2-吗啉醇盐酸盐(4b), 利用X射线单晶衍射仪测定了两化合物的晶体结构和两化合物的空间结构, 并初步分析两化合物空间结构, 化合物4a晶体属正交晶系, 空间群为P2₁2₁2, 晶胞参数为: a＝0.8718(2) nm, b＝0.7883(2) nm, c＝2.0247(6) nm, Z＝4, V＝1.3915(7) nm³, D_c＝1.328 g/cm³, F(000)＝584, R₁＝0.0399, wR₂＝0.0797, S＝1.042. 化合物4b晶体属正交晶系, 空间群为P2₁2₁2₁, 晶胞参数为: a＝0.71035 (9) nm, b＝0.77703(10) nm, c＝2.9820(4) nm, Z＝4, V＝1.6318(4) nm³, D_c＝1.318 g/cm³, F(000)＝688, R₁＝0.0520, wR₂＝0.1108, S＝0.994.     

硫、氮双齿配体与Cd(II)和Hg(II)配合物的合成与表征

以HMFC[(反)-肉桂酰基二茂铁缩(S)-甲基二硫代碳酰腙]与HBFC[(反)-肉桂酰基二茂铁缩(S)-苄基二硫代碳酰腙]两种Schiff碱分别与醋酸镉[Cd(OAc)₂•2H₂O]、醋酸汞[Hg(OAc)₂]反应, 合成了6个未见文献报道的配合物Cd(MFC)₂•H₂O, Cd(MFC)•OAc, Cd(BFC)₂, Hg(MFC)₂, Hg(MFC)•OAc, Hg(BFC)₂, 考察了其物理性质, 并利用元素分析、IR, ¹H NMR及摩尔电导表征了其组成、可能结构, 推断了配位过程. 结果表明: 这两种Schiff 碱都是反式双齿配体, 经烯硫醇化并失去质子后, 以负硫离子与过渡金属离子形成共价键, 氮原子与中心金属离子形成配位键.     

室温下电化学活化CO2与环氧化合物反应合成环碳酸酯

室温下用铝为牺牲阳极, 以四丁基溴化铵/N,N-二甲基甲酰胺作电解质溶液, 在无隔膜电解池中电化学活化CO₂, 与环氧化合物反应, 合成了环状碳酸酯. 考察了不同电极材料、导电盐、CO₂的压力以及溶剂等因素对电合成结果的影响, 结果表明以Pt为阴极, 在0.05 mol•L^－1 Bu₄NBr/DMF电解质溶液中和4 MPa CO₂下, 环状碳酸酯产率可高达65%～98%.     

利用薯蓣皂甙元完整骨架形式合成1α,25-二羟基维生素D3

首次利用薯蓣皂甙元的完整骨架经16步反应以7.6%的总收率合成了骨化三醇(1α,25-二羟基维生素D₃)的光化反应前体. 3-苄基保护的薯蓣皂甙元经还原开E/F环产生3,16,26-胆甾三醇-3-苄醚(5). 除去化合物5 C-16羟基后, 其C-26羟基经消除和羟基化反应转移到C-25位. 目标分子A/B环结构单元通过薯蓣皂甙元A/B环的官能团转化被构筑. 按照已知的光化反应, (1S,3R)-胆甾-5,7-二烯-1,3,25-三醇能被转化成为1α,25-二羟基维生素D₃.     

4-(色酮-3-基)-3-乙氧羰基-1,4,5,6,7,8-六氢-5-氧代-2,7,7-三甲基喹啉的一步合成

报道了用3-甲酰基色酮、5,5-二甲基-1,3-环己二酮、乙酰乙酸乙酯与醋酸铵一步法合成4-(色酮-3-基)-3-乙氧羰基-1,4,5,6,7,8-六氢-5-氧代-2,7,7-三甲基喹啉类化合物, 对其结构进行了表征, 并分析了代表性化合物2f的晶体结构. 2f晶体属于单斜晶系, P2/c空间群, 所得晶胞参数为: a＝2.0255(4) nm, b＝0.9132(2) nm, c＝1.4066(3) nm, β＝121.60(3)°, V＝2.2159(8) nm³, Z＝4, D_c＝1.335 g/cm³, μ＝0.209 mm^－1, F(000)＝736, R₁＝0.0556, wR₂＝0.1248.     

2,5-二乙氧甲酰氨基-1,3,4-噻二唑超分子化合物的合成和晶体结构

报道了一种用1,6-二取代二硫脲在DMF中加热回流直接脱H₂S关环合成2,5-二取代1,3,4-噻二唑类化合物的新方法, 并用此方法合成了2,5-二乙氧甲酰氨基-1,3,4-噻二唑. 用元素分析、核磁共振氢谱、红外光谱进行了表征, 用X射线单晶衍射法确定了其单晶结构. 晶体属单斜晶系, P2₁/c空间群, a＝1.0093(4) nm, b＝0.9035(4) nm, c＝1.2924(6) nm, β＝96.785(9)°, V＝1.1703(9) nm³, Z＝4, D_c＝1.477 g/cm³, F(000)＝544, μ＝0.287 mm^－1. 该化合物通过分子间氢键形成了一种二维网状结构的超分子, 由于分子间的作用力使其分子又沿c轴呈层状堆积.     

A stereo-controlled route to conjugated E-enediynes

3-Ene-1, 5-diynes are important components of many enediyne antitumor agents and luminescent materials. A stereo-controlled approach to the synthesis of E-enediynes was developed, and it consists of the following two steps: (1) a mild and economical synthesis of dihalo vinyl derivatives via addition of CuBr₂ to alkynes; (2) the Sonogashira coupling reaction of the dihalo vinyl derivatives with terminal alkynes to form conjugated enediynes. Translated from Chinese Journal of Organic Chemistry, 2006, 26(12): 1682–1685 [译自: 有机化学]     

A general access to 1,1-cyclopropane aminoketones and their conversion into 2-benzoyl quinolines

1,1-Cyclopropane aminoketones were efficiently synthesized in high yields by the tandem reaction of α-amino aryl ketones with vinyl sulfonium salts using DBU as the base in CH(2)Cl(2). This methodology was utilized to synthesize 2-benzoyl quinolines.     

Synthesis of methyl-1-(tert-butoxycarbonylamino)-2-vinylcyclopropanecarboxylate via a Hofmann rearrangement utilizing trichloroisocyanuric acid as an oxidant

A trichloroisocyanuric acid (TCCA) mediated Hofmann rearrangement was utilized to synthesize methyl-1-(tert-butoxycarbonylamino)-2-vinylcyclopropanecarboxylate. A variety of functional groups are tolerated in this reaction including vinyl, cyclopropyl, pyridyl, aryl, benzyl, and nitro groups.     

Linear-selective hydroformylation of vinyl ether using Rh (acac)(2,2′-bis{(di[1H-indol-1-yl]phosphanyl)oxy}-1,1′-binaphthalene) – Possible way to synthesize 1,3-propanediol

Three bidentate phosphoramidite ligands were synthesized, characterized, and employed in Rh-catalyzed hydroformylation of vinyl ethers. The complex Rh(acac)(2,2′-bis{(di[1H-indol-1-yl]phosphanyl)oxy}-1,1′-binaphthalene} (acac = acetylacetone) (Rh- L4 ) was also synthesized and characterized. Rh- L4 showed good regioselectivity for the hydroformylation of vinyl ethers under mild reaction conditions: 2 MPa of syngas, 1:1 (H₂/CO) substrate/catalyst molar ratio 1000:1, and 60 °C. The linear selectivity was up to 98%, and in most cases was about 80%, with no hydrogenation product formation observed, which could be a potential way to synthesize 1,3-propanediol. A mechanism study including density functional theory computational analysis showed that both Rh–H and CO insertion steps in the hydroformylation of vinyl ether were linear-preferred in our catalyst system.     

From metal‐catalyzed radical telomerization to metal‐catalyzed radical polymerization of vinyl chloride: Toward living radical polymerization of vinyl chloride

The metal‐catalyzed radical polymerization of vinyl chloride (VC) in ortho‐dichlorobenzene initiated with various activated halides, such as α,α‐dihaloalkanes, α,α,α‐trihaloalkanes, perfloroalkyl halides, benzyl halides, pseudohalides, allyl halides, sulfonyl halides, α‐haloesters, α‐halonitriles, and imidyl halides, in the presence of Cu(0)/2,2′‐bipyridine, Fe(0)/o‐phenantroline, TiCp₂Cl₂, and other metal catalysts is reported. The formation of the monoadduct between the initiator and VC was achieved with all catalysts. However, propagation was observed only for metals in their zero oxidation state because they were able to reinitiate from geminal dihalo or allylic chloride structures. Poly(vinyl chloride) with molecular weights larger then the theoretical limit allowed by chain transfer to VC were obtained even at 130 °C. In addition, the most elemental features of a living radical polymerization, such as a linear dependence of the molecular weight and a decrease of polydispersity with conversion, were observed for the most promising systems based on iodine‐containing initiators and Cu(0), that is, I? CH₂? Ph? CH₂? I/Cu(0)/bpy (where bpy = 2,2′‐bipyridyl), at 130 °C. However, because of the formation of inactive species via chain transfer to VC and other side reactions, the observed conversions were in most cases lower than 40%. A mechanistic interpretation of the chain transfer to monomer in the presence of Cu species is proposed. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3392–3418, 2001     

Hyperbranched copolymers made from A2, B2 and type monomers (iv)--Copolymerization of divinyl sulfone with 4, 4′-trimethylenedipiperidine and N-ethylethylenediamine

The new approach for synthesis of hyperbranched polymers from commercially available A2 and type monomers was extended to synthesize hyperbranched copolymers. In this work, hyperbranched copoly(sulfone-amine) was prepared by copolymerization of divinyl sulfone (A2) with 4,4′-trimethylenedipiperidine (B2) and N-ethylethylenediamine ( ). During the reaction, secon-dary-amino groups of B2 and monomers react rapidly with vinyl groups of A2 monomers within 35 s, generating a type of intermediate containing one vinyl group and two reactive hydrogen atoms. Now the intermediates can be regarded as a new type monomer, which further polymerizes to form hyperbranched copoly(sulfone-amine). The polymerization mechanism was investigated with FTIR and LC-MSD. The degree of branching (DB) of hyperbranched copolymers increased with decreasing the ratio of 4, 4′-trimethylenedipiperidine to N-ethylethyl- enediamine, so DB can be controlled. When the initial mole ratio of B2 to was equal to or higher than four, r≥4, resulted copolymers were semi-crystalline, while copolymers with r＜3 were amorphous.     

Synthesis and spectral characteristics of vinyltetrazolinones

Several methods have been worked out to synthesize 1 - vinyl - 4 - substituted - Δ² - tetrazolin - 5 - ones. NMR spectra showed typical AMX-patterns for the vinyl protons with chemical shifts and coupling constants almost independent of the nature of the other N-substituent. From the shielding increments, it was concluded that the tetrazolinone group exercises a strong inductive electron-withdrawing effect, but only a small resonance effect on the vinyl group. This paper also describes the first cycloreversions of azide adducts, induced by electron impact. Other significant fragmentation patterns of several mono- and disubstituted tetrazolinones are discussed.     

Rhodium-catalyzed alkyne hydrothiolation with aromatic and aliphatic thiols

Alkyne hydrothiolation is a potentially attractive method for the formation of vinyl sulfides, which are valuable synthetic intermediates. Known methods for hydrothiolation using alkyl thiols are quite limited. We report herein that Tp*Rh(PPh3)2 (Tp* = hydrotris(3,5-dimethylpyrazolyl)borate) is a highly active catalyst for alkyne hydrothiolation with alkyl and aryl thiols. Hydrothiolation using alkyl thiols proceeds with excellent regioselectivity, providing convenient access to branched alkyl vinyl sulfides, which are difficult to synthesize by other means. A mixture of regioisomers is obtained when using aryl thiols, with the branched isomer as the major product, opposite that reported for other Rh complexes.     

Metal Complexes for the Vinyl Addition Polymerization of Norbornene: New Compound Classes and Activation Mechanism with B(C6F5)3/AlEt3

Classes of mainly nickel(II) and palladium(II) complexes are comparatively presented in their norbornene polymerization activity to vinyl polynorbornene when activated with methylalumoxane, MAO, tris(pentafluorophenyl)borane/triethylaluminum, B(C₆F₅)₃/AlEt₃ or even B(C₆F₅)₃ alone. Classes include Ni and Pd complexes with α-dioxime ligands, salts with [PdCl₄]²⁻ and [Pd₂Cl₆]²⁻ units, dinuclear Ni and Pd complexes with multidentate Schiff-base ligands, polynuclear Ni- and Cr/Ni-carboxylate cage complexes, and dihalo(bisphosphane) Ni and Pd complexes. The study of activation mechanism by ³¹P- and ¹⁹F-NMR together with X-ray structural data points to the formation of PdCl₂ units and “naked” Pd²⁺ cations as highly active species.     

Copper-catalyzed synthesis of aryl azides and 1-aryl-1,2,3-triazoles from boronic acids

A catalytic method was developed to synthesize aryl and vinyl azides from the corresponding boronic acids under mild and operationally simple conditions. In addition, a new one-pot procedure was developed to synthesize 1-aryl- and 1-vinyl-1,2,3-triazoles directly from boronic acids and alkynes, which avoided the need to isolate unstable azide intermediates.