Microwave-assisted cycloadditions of 2-alkynylbenzonitriles with sodium azide: selective synthesis of tetrazolo[5,1-a]pyridines and 4,5-disubstituted-2H-1,2,3-triazoles
摘要:
Under microwave irradiation (75 W), treatment of 2-alkynylbenzonitriles with 1.5 equiv of sodium azide in DMSO at 140 degrees C gave 4,5-disubstituted-2H-1,2,3-triazoles in 60-99% yields. Additionally, adding 8 equiv of ZnBr2 and using 8 equiv of sodium azide in DMF at 100 degrees C lead to the formation of tetrazolo[5,1-a]isoquinolines up to 87% yield. (C) 2009 Elsevier Ltd. All rights reserved.
The activity of a simple, commercially available copper salt, [Cu(NCMe)4](BF4) in intramolecular hydroamination reactions of alkynes and allenes is presented. Reactions were successfully carried out in technical acetonitrile in the presence of air. While attempts of alkene hydroamination failed, this catalysts was also found active in intermolecular aza-Michael reactions.
Atom-Economical Synthesis of <i>N</i>-Heterocycles via Cascade Inter-/Intramolecular C−N Bond-Forming Reactions Catalyzed by Ti Amides
作者:Hao Shen、Zuowei Xie
DOI:10.1021/ja101796k
日期:2010.8.25
Direct and efficient catalytic reactions with excellent regioselectivity for the preparation of a series of substituted isoindoles, isoquinolines, and imidazoles are reported. Reaction of C(6)H(4)(2-CN)C[triple bond]C-R with an array of amines, catalyzed by 10 mol % of [sigma:eta(1):eta(5)-(OCH(2))(Me(2)NCH(2))C(2)B(9)H(9)]Ti(NMe(2)) (1), gives a series of substituted isoindoles in very high yields
Attempts at vinyl radical carbonylation through cyclization onto carbonyl and cyano groups
作者:Pier Carlo Montevecchi、Maria Luisa Navacchia、Piero Spagnolo
DOI:10.1016/s0040-4020(98)00458-x
日期:1998.7
Sulfanylvinyl radicals 4–6, 16, produced from toluenesulfanyl radical addition to alkynes 1–3, 15, gave only products arising from cyclizationonto the thiophenyl ring and H-abstraction. No products were obtained deriving from possible 5-membered cyclizationonto the esteric or thioesteric carbonyl group. Similar results were obtained from toluenesulfanyl radical addition to alkynyl nitriles 20 and
Highly Active Palladium Catalyst for the Sonogashira Coupling Reaction of Unreactive Aryl Chlorides
作者:Dong-Hwan Lee、Young-Jun Kwon、Myung-Jong Jin
DOI:10.1002/adsc.201100747
日期:2011.11
communication reports on the β-diketiminatophosphane palladium-catalyzed copper-free Sonogashira coupling of arylchlorides with alkynes. A catalyst loading of 0.5 mol% is sufficient to achieve high performance under relatively mild reaction conditions. Furthermore, dialkynylbenzenes are efficiently prepared by one-pot double Sonogashira couplings of aryl dichlorides.
Palladium-Catalyzed Sonogashira Coupling of Aryl Mesylates and Tosylates
作者:Pui Ying Choy、Wing Kin Chow、Chau Ming So、Chak Po Lau、Fuk Yee Kwong
DOI:10.1002/chem.201001269
日期:2010.9.3
Up to speed: The first general and mild protocol for the Sonogashiracoupling of aryl mesylates is presented (see scheme). The coupling intermediate also provides facile access to 2‐substituted isoquinolines.