Organocatalytic Synthesis of Multiple Substituted Bicyclo[4.4.0]Decalin System
摘要:
An efficient and unprecedented organocatalytic reaction of gamma-nitroketones with alpha,beta-unsaturated aldehydes to give polyfunctionalized [4.4.0] bicyclic skeletons was developed. The diphenylprolinol silyl ether mediated nitro-Michael/Aldol reaction afforded the hexa-substituted decalin carboaldehydes with excellent diastereo- and enantioselectivity (up to > 99:1 dr and > 99% ee) via a formal [4 + 2] carbocyclization process.
Organocatalyzed asymmetric Michael addition by an efficient bifunctional carbohydrate–thiourea hybrid with mechanistic DFT analysis
作者:Chandra S. Azad、Imran A. Khan、Anudeep K. Narula
DOI:10.1039/c6ob02158a
日期:——
core scaffold were synthesized and examined as catalysts for the asymmetricMichael addition reaction of aryl/alkyl trans-β-nitrostyrenes over cyclohexanone and other Michael donors having active methylene. Excellent enantioselectivities (<95%), diastereoselectivities (<99%), and yields (<99%) were attained undersolvent free conditions using 10 mol% of 1d0. The obtained results were explained through
Enantio- and Diastereoselective Michael Addition Reactions of Unmodified Aldehydes and Ketones with Nitroolefins Catalyzed by a Pyrrolidine Sulfonamide
作者:Jian Wang、Hao Li、Bihshow Lou、Liansuo Zu、Hua Guo、Wei Wang
DOI:10.1002/chem.200600115
日期:2006.5.24
Chiral (S)-pyrrolidine trifluoromethanesulfonamide has been shown to serve as an effective catalyst for direct Michael addition reactions of aldehydes and ketones with nitroolefins. A wide range of aldehydes and ketones as Michael donors and nitroolefins as acceptors participate in the process, which proceeds with high levels of enantioselectivity (up to 99 % ee) and diastereoselectivity (up to 50:1
easily synthesized from 1,1′-ferrocenedicarbaldehyde and aliphatic amines in high yields. One of the ferrocenophanes served as a ligand for the copper-catalyzed oxidative coupling of 2-naphthol derivatives to give the products in good yields with up to 92 % ee, and it also efficiently catalyzed the asymmetric Michael addition reaction as an organocatalyst.
N-取代的 2-氮杂-[3]-二茂铁很容易从 1,1'-二茂铁二甲醛和脂肪胺以高产率合成。其中一种二茂铁作为配体用于铜催化的 2-萘酚衍生物氧化偶联,以高达 92% ee 的良好收率得到产物,并且它还作为有机催化剂有效催化不对称迈克尔加成反应。
Ionic Liquid-Supported (ILS) (<i>S</i>)-Pyrrolidine Sulfonamide, a Recyclable Organocatalyst for the Highly Enantioselective Michael Addition to Nitroolefins
作者:Bukuo Ni、Qianying Zhang、Kritanjali Dhungana、Allan D. Headley
DOI:10.1021/ol900003e
日期:2009.2.19
A new class of ionic liquid supported (ILS) (S)-pyrrolidine sulfonamide organocatalyst has been developed and shown to be a very effective catalyst for the asymmetric Michaeladdition reactions of ketones and aldehyde to nitroolefins with high enantio- and diastereoselectivities. This ILS organocatalyst is also easily recycled and could be reused at least five times without significant loss of its
Pyrrolidine-linker-camphor assembly: bifunctional organocatalysts for efficient Michael addition of cyclohexanone to nitroolefins under neat conditions
new class of pyrrolidinyl–camphor based bifunctionalorganocatalysts possessing varying functional linkers. Catalytic screening of these camphor–pyrrolidine linked derivatives for asymmetric Michael reaction of cyclohexanone with β-nitrostyrene was carried out. Various aryl- and heteroaryl-nitroolefins, ketones as well as aldehydes gave the corresponding Michael adducts in high chemical yields (up to