卡宾：时尚的暴君与放纵

时间:4月2日 地点:北京藏酷酒吧 主题:卡宾(Cabbeen)2004春夏发布 在这里,时尚是一种放纵更是一种姿态.卡宾的标志性细节被肆意发挥到极致,涂鸦增添了写意的色彩,印花、烫贴、拼接的手法交叉使用,毛边的梭织和针织面料结合,鞋子、腰带、包袋的系列化配套,塑造了一个全副武装的卡宾男人.

DFT Study of Mechanism of Extraction Reaction Between Germylene Carbene （H2Ge=C：） and Its Derivatives and Ethylene Oxide

The mechanism of the oxide extraction reaction between singlet germylene carbene and its derivatives X2Ge=C： （X=H, F, Cl, CH3） and ethylene oxide has been investigated with B3LYP/6-311G（d,p） method. The results show that this kind of reaction has similar mechanism, the shift of 2p lone electron pair of O in ethylene oxide to the 2p unoccupied orbital of C in X2Ge=C： gives a p→p donor-acceptor bond, thereby leading to the formation of intermediate. As the p→p donor-acceptor bond continues to strengthen, that is the C-O bond continues to shorten, the intermediate generates product （P＋C2H4） via transition state. It is the substituent electronegativity that mainly affect the extraction reactions. When the substituent electronegativity is greater, the energy barrier is lower, and the reaction rate is greater.

Ab initio Study of Mechanism of Forming Germanic Bis-Heterocyclic Compound Between Dichloro-Germylene Carbene （Cl2Ge=C：） and Formaldehyde

The mechanism of the cycloaddition reaction of forming germanic bis-heterocyclic compound between singlet dichloro-germylene carbene and formaldehyde has been investigated with CCSD（T）//MP2/6-31G^＊ method, from the potential energy profile, we predict that the reaction has two competitive dominant reaction pathways. The presented rule of this reaction： the 2p unoccupied orbital of the C atom in dichloro-germylene carbene insert the π orbital of formaldehyde from oxygen side, resulting in the formation of intermediate. In the intermediate and between two reactants, because of the two bonding π orbital in dichloro-germylene carbene and formaldehyde have occurred [2＋2] cycloaddition reaction, forming two four- membered ring compounds in which Ge and O are in the opposite orientation and in the syn-position, respectively. Because of the unsaturated property of C atom from carbene in the two four-membered ring compounds, they further reacts with formaldehyde, resulting in the generation of two germanic bis-heterocyclic compounds.

Density Functional Theory Study of Mechanism of Cycloaddition Reaction Between Dimethyl-Silylene Carbene and Acetone

The mechanism of the cycloaddition reaction between singlet dimethyl-silylene carbene and acetone has been investigated with density functional theory, From the potential energy profile, it can be predicted that the reaction has two competitive dominant reaction pathways. The presented rule of this reaction： the [2＋2] cycloaddition effect between the πorbital of dimethyl-silylene carbene and the π orbital of π-bonded compounds leads to the formation of a twisty four-membered ring intermediate and a planar four-membered ring product; The unsaturated property of C atom from carbene in the planar four-membered ring product,resulting in the generation of CH3-transfer product and silicic bis-heterocyclic compound.

广州 My Way 就是－－选择

无论如何，每个人都会面临选择。除了父母没得挑外，似乎没有什么不能选择的了，乃至于你的性别。所以，对于人外在的衣着，就更不是问题了。至于男人，一直都被认为穿衣打扮没得挑的观念实在是太老土了。在广州，你就能看到不同的男人极尽其能事的打扮自己。某种程度上，更胜于女人。

Cabbeen：颠覆时尚

3月26日下午，名为《颠覆时尚》的“卡宾（Cabbeen）”品牌时装秀在北京电影制片）摄影棚举办，北京概念98公司是本次发布会的策划及制作方，并由张舰全面提纲。

Co(Ⅲ)/Zn(Ⅱ)-catalyzed dearomatization of indoles and coupling with carbenes from ene-yne ketones via intramolecular cyclopropanation

A straightforward and efficient protocol for dearomatizing indoles is described.The reaction,catalyzed by an inexpensive Co(III)/Zn(II)catalyst,starts from easily accessible N‐pyrimidinyl indoles and ene‐yne ketones.Mild reaction conditions,high diastereoselectivity,a broad substrate scope,effective functional group tolerance,and reasonable to remarkable yields were observed.

Unexpected Chemistry from the Homogeneous Thermal Decomposition of Acetylene:An ab initio Study

The formation of the aromatic ring during the formation of polycyclic aromatic hydrocarbons (PAHs) remains controversial and the experimental evidence is still lacking. Moreover, the formation mechanism of benzene from acetylene in the gas phase has also puzzled organic chemists for decades. Here, ab initio molecular dynamics simulations and electronic structure calculations provide compelling evidence for an unexpected competitive reaction pathway in which the aromatic ring is formed through successive additions of vinylidene. Moreover, no collisions cause bond dissociation of the acetylene molecule during the formation of benzene in this work. This study reveals the key role for the vinylidene carbene and determines the lifetime of vinylidene.

Silver-catalyzed three-component reaction of phenyldiazoacetate with arylamine and imine

A new method was developed to diastereoselectively synthesize polysubstituted 1,2‐diamine compounds from the reaction of diazoesters with arylamines and diaryl imines by using the dioxazoline ligand L2‐ligated silver catalyst.The Lewis acidity of the silver catalyst affected the different types of substrate diastereoselectivities;It also led to the formation of amine‐exchange side products.

Theoretical Studies on Reaction Pathways of Samarium（Ⅱ） Carbenoid Promoteded Cyclopropanation Reaction of Ethylene

In order to have efficient and highly stereoselective cyclopropanating reagents, the cyclopropabation reaction of ethylene promoted with Samarium（Ⅱ） carbenoid [Simmons-Smith（SS）reagent] were studied by means of B3LYP hybrid density functional method. The geometries for reactants, transition states and products are completely optimized. All transition states were verified by the vibrational analysis and the intrinsic reaction coordinate （IRC） calculations. The results showed that, identical with the lithium carbenoid, CH3SmCH2X（X=Cl, Br and Ⅰ） can fairly react with ethylene via both methylene transfer pathway （pathway A） and carbometalation pathway （pathway B）. And the cyclopropanation reaction via methylene transfer pathway proceeds with a lower barrier and at lower temperatures.

Electrocatalytic hydrogen evolution from water at low overpotentials with cobalt complexes supported by redox-active bipyridyl-NHC donors

Three cobalt complexes bearing tunable,redox-active bipyridyl N-heterocyclic carbene(NHC)-based ligands have been studied for electrocatalytic hydrogen evolution from aqueous solutions.The effect of structural modifications to the ligand framework is investigated across the catalyst series,which includes a non-macrocyclic derivative(1-Co)and 16-(2-Co)and 15-(3-Co)membered macrocycles.A structure-activity relationship is demonstrated,in which the macrocyclic complexes have greater activity compared to their non-macrocyclic counterpart with the most rigid catalyst,supported by the 15-membered macrocycle,performing best overall.Indeed,3-Co catalyzes H2 evolution from aqueous pH 4 acetate buffer with a Faradaic efficiency of 97%at a low overpotential of 330 mV.Mechanistic studies are consistent with formation of a cobalt-hydride species that is subsequently protonated to evolve H2 via a heterolytic pathway.

Gold carbene chemistry from diazo compounds

Diazo compounds are generally used as carbene precursors. Traditionally, dirhodium, copper and iron catalysts were used to decompose diazo compounds to form the key metal carbene intermediates. Recently, the gold catalysts have been developed as a unique type of metal catalyst to decompose diazo compounds. The derived gold carbene showed much different characters comparing with other transition metal carbenes. They could go through a series of cycloaddition, insertion and coupling reactions. Here, the recent progress of the gold carbene chemistry from diazo compounds was reviewed, including the scope of reactions,mechanism and synthetic applications.

Binaphthyl-bridged bis-imidazolinium salts as N-heterocyclic carbene ligand precursors in the palladium-catalyzed Heck reaction

Two new bis-imidazolinium salts (4a, 4b) have been synthesized as precursors of N-heterocyclic carbenes (NHCs) from the commercially available (R)-2,2′-dihydroxy-1,1′-binaphthalene. The two bis-imidazolinium salts were used as efficient precursor of NHC ancillary ligands in the palladium-catalyzed Heck reaction. Good to excellent yields and high stereoselectivities were obtained with ethyl acrylate, acrylonitrile, and acrylamide as starting materials. The structure of bis-imidazolinium salt 4b was further characterized by single crystal X-ray diffraction analysis.

New frontiers of N-heterocyclic carbene catalysis

N-heterocyclic carbene （NHC） is both a family of strong o-donor ligands for transition metals and a privileged class of organocatalysts with synthetic potential that rivals popu- lar amine and phosphoric acid catalysts. NHC was found as a key catalytic species in thiamine diphosphate catalyzed biochemical reactions [1]. However, due to their inherent chemical instability, free NHCs had not been isolated until 1991 by Ardungo et al. [2]. Since then, the use of chiral NHC as a versatile organocatalyst has enjoyed tremendous advances and has helped to transform modem synthetic chemistry. There are over 2000 research papers dealing with both ＂N-heterocyclic carbene＂ and ＂Catalysis＂ in the past 15 years [3].

Gold-catalyzed intermolecular reaction of ynamides with 3-indolyl azides via an unexpected 1,2-alkyl migration

A gold-catalyzed intermolecular reaction of ynamides with 3-indolyl azides via the presumable α-imino gold carbenes has been developed, providing an alternative and efficient way for the synthesis of valuable 3-amino-β-carbolines in generally good to excellent yields. Importantly, this new protocol involves an unexpected 1,2-alkyl migration pathway.