In(OTf)3-mediated synthesis of substituted pyridazines
摘要:
In(OTf)(3) (4c)-mediated one-pot (4+2) cyclocondensation of gamma-alkynones 3 with N2H4(aq) in dioxane affords substituted pyridazines 5 in good yields via a sequential desulfonative or dehydrogenative aromatization. The facile transformation proceeds by a facile synthetic sequence starting with an alpha-propargylation of beta-ketosulfones 1 and a cyclocondensation of gamma-alkynones 3 with N2H4(aq). The method provides a mild and efficient condition. Moreover, this route can be enlarged to multigram scale. (C) 2015 Elsevier Ltd. All rights reserved.
Highly substituted furans from 2-propynyl-1,3-dicarbonyls and organic halides or triflates via the oxypalladation-reductive elimination domino reaction
作者:Antonio Arcadi、Sandro Cacchi、Giancarlo Fabrizi、Fabio Marinelli、Luca M Parisi
DOI:10.1016/s0040-4020(03)00588-x
日期:2003.6
an efficient straightforward entry into highly substituted furans. The best results have been obtained by using an excess of the alkyne. The process can tolerate a wide variety of important functional groups both on the alkyne and the organic halide or triflate. Under an atmosphere of carbonmonoxide, the reaction affords furan derivatives incorporating carbonmonoxide. Depending on the alkyne to organic
has been developed from the cyclization of 2‐propynyl‐1,3‐dicarbonyl compoundscatalyzed by potassium tert‐butoxide, copper(II) trifluoromethanesulfonate and triphenylphosphine using methanol/dichloromethane as the solvent under very mild conditions. Moreover, dihydrofurans could be easily transformed into the corresponding furans in the presence of trifluoroacetic acid.
General Silver-Catalyzed Hydroazidation of Terminal Alkynes by Combining TMS-N<sub>3</sub> and H<sub>2</sub>O: Synthesis of Vinyl Azides
作者:Zhenhua Liu、Peiqiu Liao、Xihe Bi
DOI:10.1021/ol501661k
日期:2014.7.18
A general hydroazidation of unactivated alkynes using silver catalysis is reported. The reactions of diverse terminal alkynes with trimethylsilyl azide (TMS-N3) in the presence of H2O afforded the corresponding vinyl azides in good to excellent yields. This reaction has a broad substrate scope, good functional group tolerance, simple operation, and high reaction efficiency, thus providing an easy access
Silver-Catalyzed Tandem C≡C Bond Hydroazidation/Radical Addition/Cyclization of Biphenyl Acetylene: One-Pot Synthesis of 6-Methyl Sulfonylated Phenanthridines
作者:Jiawei Tang、Paramasivam Sivaguru、Yongquan Ning、Giuseppe Zanoni、Xihe Bi
DOI:10.1021/acs.orglett.7b01771
日期:2017.8.4
silver-catalyzed tandem carbon–carbon triple bond hydroazidation, radical addition, and cyclization of biphenyl acetylene is described under mild conditions, leading to the formation of 6-methyl sulfonylated phenanthridines in good yields. In this novel cascade reaction, most of the atoms are incorporated into the product without cleavage of the C≡C bond. Mechanistic studies suggest the reaction should proceed
Thulium Triflate Catalyzed Hydration of 2-Substituted 4-Alkynones
作者:M.-Y. Chang、Y.-C. Cheng
DOI:10.1055/s-0035-1561652
日期:——
We report on a facile synthetic route for the preparation of substituted 1,4-diketones by thulium triflate mediated hydration of substituted 4-alkynones in MeNO 2 at 25 °C for five hours. The products were obtained in moderate to high yields.
我们报告了通过三氟甲磺酸铥介导的取代 4-炔酮在 MeNO 2 中在 25°C 下水合 5 小时制备取代 1,4-二酮的简便合成路线。以中等至高产率获得产物。