نتایج جستجو برای: alkynes

تعداد نتایج: 3647  

Journal: :Organic letters 2009
Chandra M Rao Volla Pierre Vogel

FeCl(2) catalyzes the oxidative C-C cross-coupling of tertiary amines with terminal alkynes into propargylamines using (t-BuO)(2) as oxidant. The reaction can be applied to aromatic and aliphatic amines and alkynes without solvent. High chemoselectivity for aminomethyl groups is due to a steric factor.

Journal: :Chemical communications 2015
Srimanta Manna Rishikesh Narayan Christopher Golz Carsten Strohmann Andrey P Antonchick

We have developed a novel method for the regioselective annulation of 2-nitrosopyridines with variably substituted alkynes under mild reaction conditions. This approach allows the annulation of alkynes with 2-nitrosopyridines under reagent- and catalyst-free reaction conditions. The developed method shows excellent functional group tolerance and provides easy access to N-oxide-imidazo[1,2-a]pyr...

Journal: :Organic & biomolecular chemistry 2018
Nuannuan Ma Peihe Li Zheng Wang Qipu Dai Changwen Hu

An efficient Pd-catalyzed decarboxylation/cyclization of aroyloxycarbamates to realize substituted indoles has been disclosed. Terminal alkynes as the coupling partners lead to site specific 2-substituted indoles through two pathways, while internal alkynes with aroyloxycarbamates can be transformed to 2,3-disubstituted indoles directly. This protocol is further demonstrated by the efficient sy...

Journal: :Organic letters 2013
Ze-Feng Xu Chen-Xin Cai Jin-Tao Liu

The copper-catalyzed highly regioselective reaction of internal alkynes with diaryliodonium salts was achieved for the first time. α-Arylketones were obtained in moderate to good yields from arylpropargylic alcohols or aryl alkyl alkynes under mild conditions. It was found that the two kinds of substrates underwent two different arylation-oxygenation pathways under different reaction conditions...

2014
Mohammed H. Al-huniti Salvatore D. Lepore

The conversion of alkynes to their corresponding vinyl triflates in the presence of stoichiometric TMS-triflate was greatly facilitated by the triflate salt of several transition metal catalysts most especially Zn(OTf)2. Products are formed in high regioselectivity under mild conditions. Internal alkynes bearing an aryl substituent afford vinyl triflates with a modest preference for the Z-isome...

Journal: :Journal of the American Chemical Society 2018
Erica K J Lui Jason W Brandt Laurel L Schafer

An anti-Markovnikov selective hydroamination of alkynes with N-silylamines to afford N-silylenamines is reported. The reaction is catalyzed by a bis(amidate)bis(amido)Ti(IV) catalyst and is compatible with a variety of terminal and internal alkynes. Stoichiometric mechanistic studies were also performed. This method easily affords interesting N-silylenamine synthons in good to excellent yields ...

Journal: :Organic & biomolecular chemistry 2012
Weiming Yuan Shengming Ma

An efficient and practical copper-catalyzed highly regio- and stereoselective borylcupration of internal alkynes with bis(pinacolato)diboron using a catalytic amount of K(2)CO(3) as base producing Z-alkenylboron compounds has been demonstrated by applying the ligand effect: commercially available electron-rich tris(p-methoxyphenyl) phosphine ensures a smooth and efficient reaction. Functionaliz...

2016
Adrián Gómez-Suárez Yoshihiro Oonishi Anthony R Martin Steven P Nolan

Due to the synthetic advantages presented by the dual-gold-catalysed hydrophenoxylation of alkynes, a thorough study of this reaction was carried out in order to fully define the scope and limitations of the methodology. The protocol tolerates a wide range of functional groups, such as nitriles, ketones, esters, aldehydes, ketals, naphthyls, allyls or polyphenols, in a milder and more efficient...

2015
Dongxue Chen Dantong Wang Wei Wu Linfei Xiao Rajender S. Varma

SnCl4·5H2O is a highly efficient catalyst in the hydration of terminal alkynes that affords carbonyl compounds in high to good yields. Under the optimized reaction conditions, the moderate to excellent yields of corresponding ketones were obtained when the aromatic and aliphatic terminal alkynes were used as substrates. With using diphenylacetylene as an internal alkyne, the corresponding keton...

2008
Ganapati V. Shanbhag K. Palraj

The hydroamination reaction offers a very attractive route for the synthesis of alkylated amines and their derivatives with no byproduct formation. Heterogeneous intermolecular hydroamination reactions of alkynes with aromatic amines using different inexpensive copper salts of hetropolyacid catalysts were investigated. Among heteropoly salts, copper salts of silicotungstic acid showed highest a...

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