The synthesis and properties of multifunctional thioureas bearing a variety of functional groups at a position remote from the thiourea moiety are described. A 1,5-disubstitutedtriazole tether connected with a thiourea and another functional group was synthesized via ruthenium catalyzed Huisgen cycloaddition. We demonstrate the utility of the synthetic thioureas as asymmetric catalysts and probes
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。
Synthesis of a New N-Diaminophosphoryl-N′-[(2S)-2-pyrrolidinylmethyl]thiourea as a Chiral Organocatalyst for the Stereoselective Michael Addition of Cyclohexanone to Nitrostyrenes and Chalcones - Application in Cascade Processes for the Synthesis of Polyc
作者:Carlos Cruz-Hernández、Eduardo Martínez-Martínez、Perla E. Hernández-González、Eusebio Juaristi
DOI:10.1002/ejoc.201801339
日期:2018.12.31
novel chiralthiourea containing a segment of privileged (2S)‐2‐pyrrolidinylmetan‐amine as well as a hydrophobic phosphoramide framework is described. The new organocatalyst exhibited good performance in asymmetricMichaeladditions, in a variety of systems including the formal [3+3] cyclization of cyclohexanone with arylidenepyruvates through a cascade process, which involves the asymmetric Michael
benzenesulfonic acid (DBSA) leads to highly effective and selective organocatalysts in water. The in situ generated catalysts catalyze highly stereoselective desymmetrization of prochiral ketones via directaldol reactions (up to >16:1 dr, >99% ee) in water using micelle as reaction media. The current strategy was also applied in asymmetric Michael addition leading to a catalytic system with good activity
Asymmetric Michael addition catalysed by sugar-based prolinamides in solvent-free conditions
作者:Jyoti Agarwal、Rama Krishna Peddinti
DOI:10.1016/j.tetlet.2010.10.148
日期:2011.1
Sugar-based prolinamides derived from glucosamine have been developed as organocatalysts for the asymmetric Michael addition between cyclohexanones and nitroolefins. Numerous polar and nonpolar solvents and additives have been screened in the current study. The organocatalyst 1c in the presence of benzoic acid as additive catalysed the reaction under neat conditions to afford Michael adducts in high