Reaction of 4-arylmethylene-3-phenylisoxazolones and 4-arylmethylene-1,3-diphenylpyrazolones with enamines and nucleophilic heterocycles
作者:David C. Cook、Alexander Lawson
DOI:10.1039/p19740001112
日期:——
4-Arylmethylene-3-phenylisoxazolones (1) and 4-arylmethylene-1,3-diphenylpyrazolones (2) were treated with enamines (8), 3-phenylisoxazol-5(4H)-one (4), 1,3-diphenylpyrazol-5(4H)-one (6), and 2-phenyloxazol-5(4H)-one (3). The enamines were β-alkylated to give 1:1 adducts (9) and (10). The reaction of (1) with (6) and (2) with (4) gave symmetrical benzylidenedi-isoxazolones and -pyrazolones (7). 2-
Diastereo- and Enantioselective Synthesis of Spiro-Pyrrolidine-Pyrazolones by Squaramide-Catalyzed Cascade Aza-Michael/Michael Reactions
作者:Jun-Hua Li、Hongliang Wen、Lei Liu、Da-Ming Du
DOI:10.1002/ejoc.201600316
日期:2016.5
new method was developed to rapidly generate a series of spiro-pyrrolidine-pyrazolones by using a squaramide-catalyzedcascade aza-Michael/Michael addition of either tosylaminomethyl enones or enoates to unsaturated pyrazolones. This tandem reaction sequence proceeded well by using 5 mol-% of a chiral bifunctional tertiary amine squaramide catalyst to afford the desired products in good to excellent
Organocatalyzed Cascade Aza-Michael/Michael Addition for the Asymmetric Construction of Highly Functionalized Spiropyrazolone Tetrahydroquinolines
作者:Jun-Hua Li、Da-Ming Du
DOI:10.1002/asia.201402706
日期:2014.11
An organocatalyzed diastereo‐ and enantioselectivecascadeaza‐Michael/Michaeladdition of 2‐tosylaminoenones to unsaturated pyrazolones has been developed to afford novel chiral spiropyrazolone tetrahydroquinolines containing three contiguous stereocenters. This cascade reaction proceeded well with 2 mol % chiral bifunctional tertiary amine squaramide catalyst to give the desired products in excellent
Enantioselective Synthesis of Unsymmetrical Diaryl-Substituted Spirocyclohexanonepyrazolones through a Cascade [4+2] Double Michael Addition
作者:Jin-Xin Zhang、Nai-Kai Li、Zhao-Min Liu、Xiao-Fei Huang、Zhi-Cong Geng、Xing-Wang Wang
DOI:10.1002/adsc.201200925
日期:2013.3.11
ortho‐fluorobenzoic acid is an efficient catalyst system for the doubleMichaeladdition of arylidenepyrazolones with α,β‐unsaturated ketones, providing chiral unsymmetrical 6,10‐diaryl‐substituted spiro[cyclohexanone‐pyrazolone] derivatives in high yields (up to 98%) with good diastereoselectivities and excellent enantioselectivities (up to 88:12 dr, 99% ee).