Multi-component synthesis of methylene bis isoxazolo[4,5-b]-pyridine-N-oxides
摘要:
A three component one-pot protocol was investigated for the synthesis of methylene bis isoxazolo[4,5-b]-pyridine-N-oxides from commercially available materials. (C) 2010 E. Rajanarendar. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
to be good CC electrophilic acceptors for the construction of various azaarene-containing Michael addition products. This method provides an efficient and environmentally benign method for the one-potsynthesis of biologically important azaarene-substituted isoxazole derivatives in good yields. The important aspects of the present methodology are the use of non-toxic solvent, that it is catalyst free
A Fast and Highly Efficient Protocol for Synthesis of Pyrrolo[2,3-d]isoxazoles and a New Series of Novel Benzyl Bis-pyrrolo[2,3-d]isoxazoles Using Task-Specific Ionic Liquids as Catalyst and Green Solvent
We report a mild, fast, highly efficient and eco-friendly protocol for the green synthesis of pyrrolo[2,3-d]isoxazoles and a new series of novel benzyl bis-pyrrolo[2,3-d]isoxazoles from nitro styrylisoxazoles in SnCl(2)-ionic liquid by reductive cyclization. These reactions were performed at ambient temperature which resulted in good yields in short reaction time, without requiring any organic solvent
DBU-Catalyzed Inter- and Intramolecular Double Michael Addition of Donor–Acceptor Chromone-Pyrazolone/Benzofuranone Synthons: Access to Spiro-Pyrazolone/Benzofuranone-Hexahydroxanthone Hybrids
作者:Qi Di Wei、Yi-Ming Yao、Shun-Qin Chang、Wu-De Yang、Min-Yi Tian、Xiong-Li Liu、Ying Zhou
DOI:10.1055/s-0037-1610728
日期:2020.1
A DBU-catalyzed inter- and intramolecular double Michael addition of donor–acceptor chromone-pyrazolone/benzofuranone synthons and 3-methyl-4-nitro-5-alkenylisoxazoles has been established, which constructed structurally diverse spiro-pyrazolone/benzofuranone-hexahydroxanthone hybrids bearing five consecutive stereocenters in good yields (up to 91%) with high diastereoselectivities (up to >20:1 dr)
Chiral Cyclopropenimine‐catalyzed Asymmetric Michael Addition of Bulky Glycine Imine to α,β‐Unsaturated Isoxazoles
作者:Yu‐Jun Bai、Mei‐Ling Cheng、Xiao‐Hui Zheng、Sheng‐Yong Zhang、Ping‐An Wang
DOI:10.1002/asia.202200131
日期:2022.6
A highly efficient asymmetric Michaeladdition of bulky glycine imine to α,β-unsaturated isoxazoles has been achieved by using 5 mol% of chiral cyclopropenimine (CSB-1) as a chiral organosuperbase catalyst under mild conditions to provide Michael adducts in excellent yields and stereoselectivities.