Highly Diastereo- and Enantioselective Cross-Cascade Reactions of Different Enones
作者:Huicai Huang、Wenbin Wu、Kailong Zhu、Juan Hu、Jinxing Ye
DOI:10.1002/chem.201204520
日期:2013.3.18
Cascading ketones! The first highly efficient asymmetric cross‐cascade reaction of different α,β‐unsaturated ketones catalyzed by an easily prepared bulky primary amine salt has been developed. It affords the corresponding diverse products containing three to four contiguous stereocenters with excellent enantio‐ and diastereoselectivities (see scheme).
Solvent Dependent Divergent Reactivity of Electron‐Rich Dienones with and without Visible Light: Access to Cyclopropanated Furans and Butenolides
作者:Jayanta Saha、Indrajit Das
DOI:10.1002/adsc.201901273
日期:2020.2.6
hexafluoroisopropanol (HFIP) as an additive promotes intramolecular radical cascade cyclization to afford cyclopropanated furans. Molecular dioxygen in the air serves as a redoxcatalyst in this reaction which is proposed to proceed through a radical cation intermediate generated by single‐electron transfer (SET) from a phototransient dienone to oxygen. By changing the solvent from isopropanol to HFIP
Highly diastereoselective and enantioselective Michael addition of 5H-oxazol-4-ones to α,β-unsaturated ketones catalyzed by a new bifunctional organocatalyst with broad substrate scope and applicability
作者:Huicai Huang、Kailong Zhu、Wenbin Wu、Zhichao Jin、Jinxing Ye
DOI:10.1039/c1cc15928c
日期:——
A new thiourea-tertiary amine bifunctional catalyst derived from L-tert-leucine was developed and provides excellent stereocontrol in a novel and direct Michaeladdition of 5H-oxazol-4-ones to alpha,beta-unsaturated ketones with much broad substrate scope. The conjugate addition products with chiral vicinal quaternary and tertiary stereocenters can be easily transformed to structurally interesting
A Novel Synthesis of Aporphinesvia 3-Phenylphenethylamines
作者:Max Gerecke、Arnold Brossi
DOI:10.1002/hlca.19790620520
日期:1979.7.17
rac-1,2,10-Trimethoxy-aporphine (14) and rac-2-ethoxy-10,11-dimethoxyaporphine (27) have been synthesized from the 3-phenylphenethylamines 9 and 22 by a newroute. The 8-phenyl-3,4-dihydroisoquinolines 11 and 24, the oxo-aporphines 12 and 25 and the rac-nor-aporphines 13 and 26 were obtained as intermediates.
Enzyme-Catalyzed Cascade Michael/Cyclization Reaction for the Synthesis of 3,4-Dihydropyran Derivatives by Using a Protease
作者:Xuan Ding、Xue-Dong Zhang、Chun-Lin Dong、Zhi Guan、Yan-Hong He
DOI:10.1007/s10562-017-2275-2
日期:2018.2
the Michael/cyclizationreaction between dimedone and aryl or alkyl substituted α,β-unsaturated ketones or ester for the synthesis of 3,4-dihydropyran derivatives. The products were obtained in moderate to excellent yields (46–95%) with certain enantioselectivities (up to 18% ee) for 27 examples. This process afforded a potential biocatalytic approach as alternative to chemical synthesis for 3,4-dihydropyran