Design, synthesis and structure of new chiral squaric acid monoaminoalcohols and diaminoalcohols and their use as catalysts in asymmetric reduction of ketones and diketones
Many chiral squaricacid aminoalcohols and C2-symmetric diaminoalcohols have been synthesized and their in situ formed chiral boron heterocycles have been used as catalysts for the enantioselective reduction of prochiral ketones and diketones by borane to give alcohols with up to 99% enantiomeric excess and 99% yield. The effects of solvent, catalyst–substrate ratio and temperature were also investigated
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).
Chiral monoaminoalcohols and diaminoalcohols of squaric acid: new catalysts for the asymmetric reduction of ketones by borane
作者:Haibing Zhou、Shoumao Lü、Rugang Xie、Albert S.C Chan、Teng-Kuei Yang
DOI:10.1016/s0040-4039(00)02162-6
日期:2001.2
Two series of newchiral ligands, squaric acid aminoalcohols and C2-symmetric squaric acid diaminoalcohols have been synthesized. The chiral oxazaborolidines formed in situ from these ligands have been used in the enantioselective borane reduction of prochiral ketones and diketones to afford alcohol products with up to 99% enantiomeric excesses. The structures of the ligands have an obvious effect
Olefination of dialkyl squarates 1–5 with several ylides 6 and phosphonates 7 gave the corresponding alkylidene products 8–12. In the case of Horner-Emmonsreactions, stereoselective formation of Z-alkylidene products was observed. An acid-catalyzed hydrolysis of 8–12 gave squarylacetic acid esters 13.
Inhibitors of squalene synthetase and protein farnesyltransferase
申请人:Abbott Laboratories
公开号:US05783593A1
公开(公告)日:1998-07-21
The present invention provides a compound of the formula ##STR1## which inhibit squalene synthetase and cholesterol biosynthesis and are useful in the treatment of e.g., hyperlipidaemia, atherosclerosis, or fungal infections, processes for the preparation of the compounds of the invention, intermediates useful in these processes, and pharmaceutical compositions containing the compounds.