نتایج جستجو برای: alkynes

تعداد نتایج: 3647  

2011
Deyun Qian Junliang Zhang

A straightforward, efficient, and reliable redox catalyst system for the Au(I)/Au(III)-catalyzed Sonogashira cross-coupling reaction of functionalized terminal alkynes with arylboronic acids under mild conditions has been developed.

Journal: :Organic & biomolecular chemistry 2012
Sandra Medina Alvaro González-Gómez Gema Domínguez Javier Pérez-Castells

2-Allyl-1-vinyl-β-carbolines and dihydropyrrolo-β-carbolines react with activated internal alkynes through novel rearrangement reactions leading to complex polycyclic structures. Favored reaction pathways depend on reaction conditions and on the presence of gold catalysts. In particular, upon reaction with 2 equiv. of the alkyne, new hexacyclic structures 10 are formed with total stereocontrol.

Journal: :Chemical communications 2011
Soo Min Kim Ji Hoon Park Young Keun Chung

Solvolysis of Au(PPh(3))PF(6) afforded Au(PPh(3))OPOF(2) which is an effective catalyst in the intramolecular [4+2] cycloaddition of unactivated dienynes bearing a terminal alkyne.

Journal: :Chemical communications 2007
Doo Seong Choi Jin Hong Kim Ueon Sang Shin Ravindra R Deshmukh Choong Eui Song

By employing superacidic fluoroantimonate ionic liquid (IL), [bmim][Sb(2)F(11)], as catalyst, not only thermodynamically-controlled but also kinetically-controlled Friedel-Crafts alkenylations of arenes with alkynes have been realized for the first time.

Journal: :Dalton transactions 2013
Chanjuan Xi Zelin Sun Yongbing Liu

An effective regioselective cyclotrimerization of terminal alkynes is achieved by the direct utilization of NiCl2·6H2O, Zn, and 2-(benzimidazolyl)-6-(1-(arylimino)ethyl)pyridine in one step under ambient temperature.

Journal: :Chemical communications 2011
Masumi Itazaki Masahiro Kamitani Hiroshi Nakazawa

Catalytic trans-selective hydrogermylation of terminal and internal alkynes was attained by a methyliron complex, CpFe(CO)(2)(Me), and a bis(germyl)hydridoiron(IV) complex as a catalyst precursor. The structures of (Z)-triphenyl-(2-phenylethenyl)germane and the bis(germyl)hydridoiron(IV) complexes CpFe(CO)(H)(GeR(3))(2) (R = Et, Ph) were confirmed by single crystal X-ray diffraction studies.

Journal: :Chemical science 2013
Yanzhao Wang Lianzhu Liu Liming Zhang

The Fischer indole synthesis is perhaps the most powerful method for indole preparation, but it often suffers from low regioselectivities with unsymmetric aliphatic ketone substrates and strong acidic conditions and is not suitable for α,β-unsaturated ketones. In this article, we disclose an efficient synthesis of N-protected indoles from N-arylhydroxamic acids/N-aryl-N-hydroxycarbamates and a ...

2016
Gerald Kehr Gerhard Erker

The 1,1 carboboration reaction of a variety of metal-substituted alkynes with simple trialkylboranes R3B yields the respective alkenylboranes (Wrackmeyer reaction). The use of the strongly electrophilic R-B(C6F5)2 reagents allows for much milder reaction conditions and gives good yields of the respective bulky alkenylboranes from conventional terminal alkynes by means of 1,2-hydride migration. ...

Journal: :The Journal of organic chemistry 2005
Jin-Heng Li Yun Liang Ye-Xiang Xie

An efficient method for palladium-catalyzed homocoupling reaction of terminal alkynes in the synthesis of symmetric diynes is presented. The results showed that both Pd(OAc)(2) and CuI played crucial roles in the reaction. In the presence of 2 mol % Pd(OAc)(2), 2 mol % CuI, 3 equiv of Dabco, and air, homocoupling of various terminal alkynes afforded the corresponding symmetrical diynes in moder...

Journal: :Chemical communications 2009
Muriel Durandetti Lucie Hardou Marie Clément Jacques Maddaluno

Reaction of Ni(0) in the presence of iodoarylethers leads, after syn intramolecular carbonickelation of the triple bond, to nucleophilic vinylnickels which can be trapped, in a tandem process, by various electrophiles introduced at the onset of the reaction.

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