A Simple One-Pot Synthesis of 2-Aryl-5-alkyl-Substituted Oxazoles by Cs2CO3-Mediated Reactions of Aromatic Primary Amides with 2,3-Dibromopropene
作者:Jayanta Ray、Nasima Yasmin
DOI:10.1055/s-0029-1217995
日期:2009.10
A simple and efficient method for the synthesis of 2-aryl-5-alkyl-substituted oxazoles has been developed. A series of 2,5-disubstituted oxazoles were synthesized in a single step by Cs2CO3-mediated reactions of aromatic primary amides with 2,3-dibromopropene.
Readily switchable one-pot 5-exo-dig cyclization using a palladium catalyst
作者:Jaishree K. Mali、Balaram S. Takale、Vikas. N. Telvekar
DOI:10.1039/c6ra25857c
日期:——
A convenient, ligand-free, Pd(OAc)2-catalyzed one-pot reaction has been developed for the synthesis of oxazolines and oxazoles from easily available acid chlorides and propargylamine. The reaction pathways could be easily modulated to selectively obtain oxazolines or oxazoles by merely changing the additives. This method proceeds via in situ sequential nucleophilic addition/elimination reactions followed
Synthesis of oxazoles through Pd-catalyzed cycloisomerization–allylation of N-propargylamides with allyl carbonates
作者:Akio Saito、Koichi Iimura、Yuji Hanzawa
DOI:10.1016/j.tetlet.2010.01.018
日期:2010.3
In the presence of Pd-2(dba)(3)-Cy3P catalyst, IPr center dot HCl salt [IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene], and Cs2CO3, N-propargylarnicles react with allyl carbonates to give 2,5-disubstituted oxazoles having homoallyl groups through the tandem cycloisomerization-allylation. (C) 2010 Elsevier Ltd. All rights reserved.
Erratum to “Zn(OTf)2-catalyzed, microwave-promoted synthesis of 2-substituted 5-methyloxazoles from propargylic amides” [Tetrahedron Lett. 60 (2019) 777–779]
The versatile conversion of propargylic amides to the respective 2-substituted 5-methyloxazoles was efficiently catalyzed by Zn(OTf)2 (5 mol%) under microwave irradiation in toluene. The method was applicable to a wide range of aliphatic, aromatic and heteroaromatic propargylic amides and thus represents a useful method which is complementary to the existing metal-catalyzed protocols, considering the