نتایج جستجو برای: acetylenic esters

تعداد نتایج: 28977  

Fatemeh Sheikholeslami-Farahani

A novel, convenient and efficient three-component reaction for synthesizing substituted pyrroles from primary amines and electron deficient acetylenic compounds in the presence of ammonium thiocyanate in water leads to the formation of pyrroles in good yields.

Journal: :Chemical communications 2015
Shivakrishna Kallepu Krishna Kumar Gollapelli Jagadeesh Babu Nanubolu Rambabu Chegondi

A high yielding metal-catalysed Conia-ene reaction of 2-acetylenic ketones for the synthesis of bicyclo[3.n.1]alkenes has been developed. This simple and efficient 6-endo-dig-cyclization protocol enables the synthesis of a wide variety of bicyclic systems, present in many natural products.

Journal: :Journal of the American Chemical Society 2005
Xiaodong Shi David J Gorin F Dean Toste

The rearrangement of 1-ethynyl-2-propenyl pivaloates to cyclopentenones catalyzed by cationic triphenylphosphinegold(I) complexes is described. The reaction tolerates both alkyl and aryl substitution at the acetylenic and olefinic positions. Importantly, the gold(I)-catalyzed rearrangement of enantioenriched propargyl pivaloates proceeds with excellent chirality transfer, thus providing a pract...

2012
Zhiyuan Ma Feng Ni Grace H C Woo Sie-Mun Lo Philip M Roveto Scott E Schaus John K Snyder

Intramolecular inverse electron demand cycloadditions of isatin-derived 1,2,4-triazines with acetylenic dienophiles tethered by amidations or transesterifications proceed in excellent yields to produce lactam- or lactone-fused α-carbolines. Beginning with various isatins and alkynyl dienophiles, a pilot-scale library of eighty-eight α-carbolines was prepared by using this robust methodology for...

Journal: :Chemical communications 2013
Watson K-W Ho Siu-Fung Lee Chi-Hin Wong Xiao-Ming Zhu Chak-Shing Kwan Chun-Pong Chak Paula M Mendes Christopher H K Cheng Ken Cham-Fai Leung

Type III-B first generation [3]rotaxane and second generation [4]rotaxane dendrimers have been synthesized via (1) a modified copper-catalyzed alkyne-azide cycloaddition (CuAAC), (2) Glaser-Hay's acetylenic oxidative homo-coupling, and (3) amide formation. The dendron does not reveal obvious cytotoxicities in L929 fibroblast cells. The rotaxane dendrimers can capture ammonia and are switchable ...

Journal: :Journal of the American Chemical Society 2006
Yoshikazu Horino Michael R Luzung F Dean Toste

Cationic tri-tert-butylphosphinegold(I) serves as a catalyst in the sila-Cope rearrangement of acetylenic allylsilanes. When phenol is employed as a nucleophile, the reaction allows for the stereoselective synthesis of vinylsilanes. Alternatively, use of methanol as a nucleophile leads to cyclic vinylsilanes, which can be viewed as latent vinylsilanes that are revealed on treatment with a mild ...

Journal: :Bioscience, biotechnology, and biochemistry 2004
Satoshi Nakahara Miyako Kusano Shozo Fujioka Atsumi Shimada Yasuo Kimura

New acetylenic nematicidal compound, penipratynolene (1), methy (2'R)-4-(2'-hydroxy-3'-butynoxy)benzoate, together with two known compounds, 6-methoxycarbonylpicolinic acid (2) and 2,6-pyridinedicarboxylic acid (3), were isolated from the culture filtrate of Penicillium bilaiae Chalabuda. The structures of 1-3 were established by spectroscopic methods. The absolute configuration of 1 was confir...

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