Enantioselective construction of quaternary carbon centre catalysed by bifunctional organocatalyst.
نویسندگان
چکیده
The bifunctional thiourea-tertiary amine derivatives of simple chiral diamines serve as highly enantioselective catalysts for the Michael addition of alpha-substituted cyanoacetates to vinyl sulfones, giving an efficient protocol for the construction of an all-carbon substituted quaternary stereocentre.
منابع مشابه
Enantioselective organocatalytic Michael additions to acrylic acid derivatives: generation of all-carbon quaternary stereocentres.
Acrylic esters, thioesters and N-acryloyl pyrrole have been identified as effective electrophiles in the enantioselective Michael addition reaction with beta-keto ester pro-nucleophiles catalysed by a cinchona alkaloid derived bifunctional organocatalyst; enantiomeric excesses of up to 98% and yields of up to 96% can be obtained for a range of Michael acceptors and pro-nucleophiles.
متن کاملEnantioselective Michael addition of 3-aryl-substituted oxindoles to methyl vinyl ketone catalyzed by a binaphthyl-modified bifunctional organocatalyst.
The enantioselective conjugate addition reaction of 3-aryl-substituted oxindoles with methyl vinyl ketone promoted by binaphthyl-modified bifunctional organocatalysts was investigated. The corresponding Michael adducts, containing a quaternary center at the C3-position of the oxindoles, were generally obtained in high yields with excellent enantioselectivities (up to 91% ee).
متن کاملConstruction of bispirooxindoles containing three quaternary stereocentres in a cascade using a single multifunctional organocatalyst.
Single-step constructions of molecules with multiple quaternary carbon stereocentres are rare. The spirooxindole structural motif is common to a range of bioactive compounds; however, asymmetric synthesis of this motif is complicated due to the presence of multiple chiral centres. The development of organocatalytic cascade reactions has proven to be valuable for the construction of several chir...
متن کاملCatalytic Enantioselective Construction of All-Carbon Quaternary Stereocenters Catalytic Enantioselective Construction of All-Carbon Quaternary Stereocenters
SYNTHESIS 2006, No. 3, pp 0369–0396xx.xx.2006 Advanced online publication: 13.01.2006 DOI: 10.1055/s-2006-926302; Art ID: E14205SS © Georg Thieme Verlag Stuttgart · New York Abstract: Catalytic enantioselective construction of all-carbon quaternary stereocenters, i.e. carbon atoms bearing four different carbon substituents, poses a particular challenge in organic synthesis. This review gives a ...
متن کاملA polymer-supported Cinchona-based bifunctional sulfonamide catalyst: a highly enantioselective, recyclable heterogeneous organocatalyst.
The design, synthesis, and catalytic application of a highly enantioselective and indefinitely stable polymer-supported Cinchona-based bifunctional sulfonamide is reported.
متن کاملذخیره 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 ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Organic & biomolecular chemistry
دوره 4 11 شماره
صفحات -
تاریخ انتشار 2006