Synthesis of Chiral Polycyclic Tetrahydrocarbazoles by Enantioselective Aminocatalytic Double Activation of 2-Hydroxycinnamaldehydes with Dienals
作者:Yong-Chao Ming、Xue-Jiao Lv、Ming Liu、Yan-Kai Liu
DOI:10.1021/acs.orglett.1c02309
日期:2021.8.20
An efficient aminocatalytic enantioselective double-activation strategy has been developed that combines several different aminocatalytic modes in a cascade process, such as iminiumion, vinylogous iminiumion, trienamine, and dienamine activations. By using this strategy, 2-hydroxycinnamaldehydes worked well with various dienals via [4 + 2] cycloaddition and the oxa-Michael reaction-initiated cascade
Asymmetric organocatalytic vinylogous Michael addition triggered triple-cascade reactions of 2-hydroxycinnamaldehydes and vinylogous nucleophiles: construction of benzofused oxabicyclo[3.3.1]nonane scaffolds
作者:Hui-Chun Wu、Chen Wang、Ying-Han Chen、Yan-Kai Liu
DOI:10.1039/d0cc07761e
日期:——
An organocatalytic vinylogous Michael addition triggered triple-cascade reaction has been developed. 2-Hydroxycinnamaldehydes worked under iminiumactivation with either acyclic or cyclic ketone-derived α,α-dicyanoalkenes, yielding the benzofused oxabicyclo[3.3.1]nonanes bearing one quaternary stereocenter with excellent stereoselectivities.
Organocatalytic asymmetric cascade cyclization reaction of o-hydroxy cinnamaldehydes with diphenylphosphine oxide
作者:Haiyun Sun、Yuan Li、Wei Liu、Yang Zheng、Zhengjie He
DOI:10.1016/j.cclet.2018.01.026
日期:2018.11
highly stereoselective asymmetriccascade cyclization reaction between o-hydroxycinnamaldehydes and diphenylphosphine oxide has been achieved with 84%–99% ee and 7:1-20:1 dr under the catalysis of l -diarylprolinol silyl ether. This reaction provides a facile access to highly enantioenriched 4-diphenylphosphinyl chroman-2-ols. It also represents a novel organocatalyticasymmetric phospha-Michael addition
Organocatalytic asymmetric Michael/hemiacetalization/acyl transfer reaction of α-nitroketones with <i>o</i>-hydroxycinnamaldehydes: synthesis of 2,4-disubstituted chromans
作者:Rajendra Maity、Subhas Chandra Pan
DOI:10.1039/c8ob00078f
日期:——
An organocatalyticasymmetriccascadeMichael/hemiketalization/acyl transfer reaction between o-hydroxycinnamaldehydes and α-nitroketones is developed. Prolinol TMS ether catalyst in combination with benzoic acid was found to be the most effective for this reaction which proceeds through an equilibrium of lactols to provide a single diastereomer of enantiopure 2,4-disubstituted chromans.