Enantioselective trapping of an α-chiral carbanion of acyclic nitrile by a carbon electrophile.
نویسندگان
چکیده
An α-chiral nitrile carbanion generated by deprotonation of enantioenriched O-carbamoyl cyanohydrin was trapped in situ with ethyl cyanoformate to give the corresponding ester derivative in 92% yield and 90 : 10 er, providing the first example of trapping of an α-chiral acyclic nitrile carbanion that has been considered to be very configurationally labile.
منابع مشابه
Enantioselective synthesis of cyclopropanes that contain fluorinated tertiary stereogenic carbon centers: a chiral α-fluoro carbanion strategy.
Chiral transfer: the fluorinated sulfoximine (see scheme; Ts=p-toluenesulfonyl) was synthesized and used as the first chiral fluoromethylenation reagent for the synthesis of cyclopropanes that contain fluorinated tertiary stereogenic carbon centers in good yields, good diastereoselectivity, and excellent enantioselectivity.
متن کاملCopper-catalyzed Enantioselective Conjugate Addition Reactions of Organozinc Reagents
Conjugate addition (1,4-addition) of carbon nucleophiles to a; b-unsaturated compounds is one of the most important carbon–carbon bond-forming strategies in synthetic organic chemistry [1]. The versatility of the conjugate addition is mainly due to the large variety of nucleophiles (organometallic reagents, Michael donors, other carbanions) and acceptors (a; b-unsaturated aldehydes, ketones, ni...
متن کاملEnantioselective Cross-Coupling of meso-Epoxides with Aryl Halides
The first enantioselective cross-electrophile coupling of aryl bromides with meso-epoxides to form trans-β-arylcycloalkanols is presented. The reaction is catalyzed by a combination of (bpy)NiCl2 and a chiral titanocene under reducing conditions. Yields range from 57 to 99% with 78-95% enantiomeric excess. The 30 examples include a variety of functional groups (ether, ester, ketone, nitrile, ke...
متن کاملElectrochemical Chiral Recognition of Naproxen Using L-Cysteine/Reduced Graphene Oxide Modified Glassy Carbon Electrode
The electrochemical response of S- and R-naproxen enantiomers was investigated on L-cysteine/reduced graphene oxide modified glassy carbon electrode (L-Cys/RGO/GCE). The production of the reduced graphene oxide and L-cysteine on the surface of the glassy carbon electrode was done by using electrochemical processes. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were us...
متن کاملEnantio-Convergent Nucleophilic Substitution Reaction of Racemic Electrophiles Catalyzed by Chiral Brønsted Acid
Among the methods for asymmetric synthesis, enantioselective catalysis is one of the representatives to produce enantio-enriched molecules in an efficient and practical manner. Catalytic enantioselective nucleophilic addition to pro-chiral electrophiles such as aldehydes, ketones, imines, and electron deficient double bonds is one of the most extensively investigated reactions, and substantial ...
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:
- Chemical communications
دوره 48 23 شماره
صفحات -
تاریخ انتشار 2012