Synthesis of β-amino alcohols using the tandem reduction and ring-opening reaction of nitroarenes and epoxides
作者:Chongyang Shi、Cheng Ren、Erlei Zhang、Huile Jin、Xiaochun Yu、Shun Wang
DOI:10.1016/j.tet.2016.04.083
日期:2016.7
A high yield one-pot synthesis of β-amino alcohols from nitroarenes and 1,2-epoxides was developed, which utilizes inexpensive iron dust as a reducing agent and NH4Cl as the only additive in a 50% (v/v) ethanol solution. This new efficient synthetic approach tolerates a wide range of functionalities. The mild reaction conditions (e.g., 60 °C), together with the use of low cost and readily available
In situ slow release of isocyanates: synthesis and organocatalytic application of N-acylureas
作者:Atul K. Singh、Ruchi Chawla、Lal Dhar S. Yadav
DOI:10.1016/j.tetlet.2013.07.045
日期:2013.9
A novel, efficient, and operationally simple one-pot synthesis of both, symmetrical and unsymmetrical N-acylureas from carboxamides and in situ generated isocyanates (from N,N-dibromo-p-toluenesulfonamide) in the presence of a mild base at rt is reported. The protocol avoids the tedious isolation and purification steps of hazardous isocyanates. The first application of these acylureas to the catalysis
An efficient method for regioselective ring opening of epoxides by amines under microwave irradiation using Bi(NO<sub>3</sub>)<sub>3</sub>·5H<sub>2</sub>O as a catalyst
作者:Shobha Bansal、Yogendra Kumar、Parveen Pippal、Dipak K. Das、Panchanan Pramanik、Prabal P. Singh
DOI:10.1039/c6nj03701a
日期:——
Bismuth(III)nitrate pentahydrate, a highly efficient environmentally benign catalyst, is used for the nucleophilic ringopening of epichlorohydrin and styrene oxide with aromatic, aliphatic and heteroaromatic amines under solvent free microwave conditions reducing the reaction time drastically to afford the corresponding β-amino alcohols in good to excellent yields with high regioselectivity. The products obtained were
硝酸铋(III)五水合物,一种高效的环境友好型催化剂,用于在无溶剂微波条件下与芳香族,脂肪族和杂芳香族胺一起对环氧氯丙烷和氧化苯乙烯进行亲核开环,从而大大缩短了反应时间,从而提供了相应的β-氨基醇具有良好的收率和优异的选择性,并具有较高的区域选择性。获得的产物通过柱色谱法直接纯化,并通过1 H和13 C NMR,FTIR和质谱进行表征。
Zinc(II) Perchlorate Hexahydrate Catalyzed Opening of Epoxide Ring by Amines: Applications to Synthesis of (<i>RS</i>)/(<i>R</i>)-Propranolols and (<i>RS</i>)/(<i>R</i>)/(<i>S</i>)-Naftopidils
作者:Shivani、Brahmam Pujala、Asit K. Chakraborti
DOI:10.1021/jo062674j
日期:2007.5.1
perchlorate hexahydrate was found to be the best catalyst compared to other metal perchlorates. The counteranion modulated the catalytic property of the various Zn(II) compounds that followed the order Zn(ClO4)2·6H2O ≫ Zn(BF4)2 ∼ Zn(OTf)2 ≫ ZnI2 > ZnBr2 > ZnCl2 > Zn(OAc)2 > Zn(CO3)2 in parallelism with the acidic strength of the corresponding protic acids (except for TfOH). The applicability of the methodology
We herein report a metal- and solvent-free acetic acid-mediated ring-opening reaction of epoxides with amines. This process provides β-amino alcohols in high yields with excellent regioselectivity. Importantly, this epoxide ring-opening protocol can be used for the introduction of amines in natural products during late-stage transformations.