[3 + 2] Cycloadditions of Azides with Arynes via Photolysis of Phthaloyl Peroxide Derivatives
摘要:
Photolysis of phthaloyl peroxides yields arynes, which undergo [3 + 2] cycloadditions with azides. This reaction tolerates a variety of organic azides and phthaloyl peroxides and affords the corresponding benzotriazoles in moderate to good yields at room temperature.
Pd(0)-Catalyzedallylations of 4(5)-nitroimidazole, 1, 2-methyl-4(5)-nitroimidazole, 2, 4(5)-bromo-imidazole, 7, 4(5)-methoxyimidazole, 10, 5(6)-nitrobenzimidazole, 16a, 5(6)-methylbenzimidazole, 16b, benzotriazole, 19, and 5(6)-methylbenzotriazole, 22, were studied under several reaction conditions. Nitroimidazoles 1 and 2 were regioselectively allylated under thermodynamic control, leading to 1-allyl-4-nitro
Benzyne Click Chemistry: Synthesis of Benzotriazoles from Benzynes and Azides
作者:Feng Shi、Jesse P. Waldo、Yu Chen、Richard C. Larock
DOI:10.1021/ol800675u
日期:2008.6.1
A variety of substituted benzotriazoles have been prepared by the [3 + 2] cycloaddition of azides to benzynes. The reaction scope is quite general, affording a rapid and easy entry to substituted, functionalized benzotriazoles under mild conditions.
Sustainable Palladium-Catalyzed Tsuji–Trost Reactions Enabled by Aqueous Micellar Catalysis
作者:Nicholas R. Lee、Farbod A. Moghadam、Felipe C. Braga、Daniel J. Lippincott、Bingchun Zhu、Fabrice Gallou、Bruce H. Lipshutz
DOI:10.1021/acs.orglett.0c01329
日期:2020.7.2
reactions, can be run under micellarcatalysis conditions featuring not only chemistry in water but also numerous combinations of reaction partners that require low levels of palladium, typically on the order of 1000 ppm (0.1 mol %). These couplings are further characterized by especially mild conditions, leading to a number of cases not previously reported in an aqueous micellar medium. Inclusion of diverse
Copper-free ‘click’: 1,3-dipolar cycloaddition of azides and arynes
作者:Lachlan Campbell-Verduyn、Philip H. Elsinga、Leila Mirfeizi、Rudi A. Dierckx、Ben L. Feringa
DOI:10.1039/b812403e
日期:——
Arynes formed through fluoride-promoted ortho-elimination of o-(trimethylsilyl)aryl triflates can undergo [3 + 2] cycloaddition with various azides to form substituted benzotriazoles. The rapid reaction times and mild conditions make this an attractive variation of the classical 'click' reaction of azides and alkynes.
Tsuji–Trost allylations with palladium recovery by phosphines/Pd(0)-triolefinic macrocyclic catalysts
作者:Anna Serra-Muns、Roser Pleixats
DOI:10.1016/j.jorganchem.2010.01.033
日期:2010.4
The allylation of several nitrogen and oxygen based nucleophiles with ethyl cinnamyl carbonate under mild conditions is described. The processes take place in the absence of added base and in the presence of the precatalytic system Pd(0)-triolefinic macrocycle/1,1'-bis(diphenylphosphino) ferrocene. The macrocyclic ligand plays a key role in the recovery of the metal in the form of the initial macrocyclic complex. (C) 2010 Elsevier B.V. All rights reserved.