Alumina-Supported Cu(II), A Versatile and Recyclable Catalyst for Regioselective Ring Opening of Aziridines and Epoxides and Subsequent Cyclization to Functionalized 1,4-Benzoxazines and 1,4-Benzodioxanes
作者:Sukalyan Bhadra、Laksmikanta Adak、Subhas Samanta、A. K. M. Maidul Islam、Manabendra Mukherjee、Brindaban C. Ranu
DOI:10.1021/jo101916e
日期:2010.12.17
catalyst, alumina-supported copper(II), efficiently catalyzes the ring opening of aziridines and epoxides followed by cyclization of the corresponding intermediate to produce a variety of functionalized 1,4-benzoxazines and 1,4-benzodioxanes, respectively, in one pot without any ligand in high yields. The ring cleavages of aziridines and epoxides are highly regioselective. The catalyst is inexpensive
Highly important trans-3,4-dihydro-2H-1,4-benzoxazine moieties were easily synthesized by domino aziridine ring opening with o-bromophenols and o-chlorophenols followed by the palladium catalyzed coupling-cyclization (intramolecular C-(aryl)-N-(amide) bond formation) with good to excellent yields. (C) 2012 Elsevier Ltd. All rights reserved.
Highly Efficient Copper-Catalyzed Domino Ring Opening and Goldberg Coupling Cyclization for the Synthesis of 3,4-Dihydro-2<i>H</i>-1,4-benzoxazines
作者:R. Koteshwar Rao、Ajay B. Naidu、Govindasamy Sekar
DOI:10.1021/ol9003299
日期:2009.5.7
trans-3,4-Dihydro-2H-1,4-benzoxazine moieties can be synthesized by domino aziridine ring opening with o-iodophenols followed by the copper-catalyzed Goldberg coupling cyclization (intramolecular C(aryl)-N(amide) bond formation) with good to excellent yields.