Chiral phosphine-squaramides as enantioselective catalysts for the intramolecular Morita–Baylis–Hillman reaction
作者:Hong-Liang Song、Kui Yuan、Xin-Yan Wu
DOI:10.1039/c0cc03187a
日期:——
squaramides containing tertiary phosphine were developed as chiral bifunctional organic catalysts to promote the asymmetric intramolecularMorita-Baylis-Hillmanreaction of omega-formyl-enones. The adducts were obtained in high yields with good-to-excellent enantioselectivity (up to 93% ee).
catalysis, ferrocene could be an excellent scaffold for organocatalysts. The simple and easily accessible bifunctional ferrocene-based squaramide-phosphine shows high enantioselectivity in the intramolecularMorita–Baylis–Hillmanreaction of 7-aryl-7-oxo-5-heptenals, giving a variety of 2-aroyl-2-cyclohexenols in up to 96% ee.
Tandem Nucleophilic Addition/Oxa-Michael Reaction for the Synthesis of<i>cis</i>-2,6-Disubstituted Tetrahydropyrans
作者:Santosh J. Gharpure、J. V. K. Prasad、Kalisankar Bera
DOI:10.1002/ejoc.201402199
日期:2014.6
A Lewis acid catalyzed tandem nucleophilic addition/oxa-Michaelreaction was developed for the synthesis of cis-2,6-disubstituted tetrahydropyran (THP) derivatives in good yields with excellent diastereoselectivities. The strategy was successfully used in the construction of THP derivatives with three stereocenters in a highly stereoselective fashion.
Enantioselective intramolecular Rauhut–Currier reaction catalyzed by chiral phosphinothiourea
作者:Jing-Jing Gong、Tian-Ze Li、Kun Pan、Xin-Yan Wu
DOI:10.1039/c0cc04412a
日期:——
Chiral organophosphine-catalyzed enantioselective Rauhut-Currier reaction has been disclosed for the first time. With L-valine-derived phosphinothiourea, the intramolecular Rauhut-Currier reaction of bis(enones) was achieved in good yields (up to 99%) with excellent enantioselectivities (up to 99.4% ee).
A series of chiral bifunctional phosphinothioureas derived from l-amino acids have been developed to promote the enantioselectiveintramolecularMorita–Baylis–Hillmanreaction. The process afforded the cyclic hydroxyl enones with up to 84% ee and good yields under mild conditions.