Chiral Phase-transfer Catalysis (cptc) by Modified Cinchona Alkaloids

نویسنده

  • Rahul Palchaudhuri
چکیده

INTRODUCTION Phase-transfer catalysis (PTC) involves the use of environmentally benign organocatalysts, mild reaction conditions, and simple experimental procedures that are insensitive to air/moisture and amenable to large-scale processes. Furthermore, the use of inexpensive inorganic bases such as NaOH in place of expensive moisture-sensitive hydride, alkoxide and amide bases makes PTC an attractive option for both laboratory and industrial processes. Although PTC has been applied extensively in a

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Solution- and Solid-Phase Approaches in Asymmetric Phase-Transfer Catalysis by Cinchona Alkaloid Derivatives

Synthesis 2001, No. 11, 28 08 2001. Article Identifier: 1437-210X,E;2001,0,11,1742,1746,ftx,en;C03701SS.pdf. © Georg Thieme Verlag Stuttgart · New York ISSN 0039-7881 Abstract: The catalytic asymmetric alkylation under phase-transfer conditions of various substrates (enones, -fluoro ketones, glycineimines) promoted by chiral quaternary ammonium salts derived from cinchona alkaloids is described...

متن کامل

Isoindolinones as Michael Donors under Phase Transfer Catalysis: Enantioselective Synthesis of Phthalimidines Containing a Tetrasubstituted Carbon Stereocenter.

Readily available chiral ammonium salts derived from cinchona alkaloids have proven to be effective phase transfer catalysts in the asymmetric Michael reaction of 3-substituted isoindolinones. This protocol provides a convenient method for the construction of valuable asymmetric 3,3-disubstituted isoindolinones in high yields and  moderate to good enantioselectivity. Diastereoselectivity was al...

متن کامل

Heterogeneous enantioselective hydrogenation over cinchona alkaloid modified platinum: mechanistic insights into a complex reaction.

Modification of a metal surface by a strongly adsorbed chiral organic molecule has proven to be an interesting strategy for heterogeneous chiral catalysis. Platinum chirally modified by cinchona alkaloids, successfully applied for the enantioselective hydrogenation of alpha-ketoesters, is probably the most prominent catalyst based on this concept. Despite considerable research efforts toward un...

متن کامل

Diastereodivergent organocatalysis for the asymmetric synthesis of chiral annulated furans.

Disclosed herein is a stereoselective method for the synthesis of 2,3-furan fused carbocycles bearing adjacent quaternary and tertiary carbon stereocenters. The chemistry is based on an asymmetric addition of β-ketoesters to 2-(1-alkynyl)-2-alkene-1-ones catalysed by natural cinchona alkaloids followed by a silver-catalysed intramolecular cycloisomerisation. By exploiting the distinct catalysis...

متن کامل

9-Amino-(9-deoxy)cinchona alkaloid-derived new chiral phase-transfer catalysts.

A new class of 9-amino-(9-deoxy)cinchona alkaloid-derived chiral phase-transfer catalysts bearing amino groups was developed by using known cinchona alkaloids as the starting materials. Due to the transformation of the 9-hydroxyl group into a 9-amino functional group, the catalytic performances were significantly improved in comparison with the corresponding first generation phase-transfer cata...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2007