Efficient Synthesis of Chiral Trisubstituted 1,2-Allenyl Ketones by Catalytic Asymmetric Conjugate Addition of Malonic Esters to Enynes.
نویسندگان
چکیده
An N,N'-dioxide/scandium(III) complex catalyzed, highly efficient conjugate addition of malonic esters to enynes is described. A range of trisubstituted 1,2-allenyl ketones were obtained in high yields (up to 99 %) with good d.r. (up to 95/5) and excellent ee values (97 %-99 %). Moreover, the products could be easily transformed into chiral furan and 5-hydroxypyrazoline derivatives, both of which are important skeletons of many biologically active compounds and pharmacologicals.
منابع مشابه
An Efficient Protocol for the Synthesis of Carboacyclic Nucleosides via Aza-Conjugate Addition Reaction
A new efficient method for the synthesis of carboacyclic nucleosides as biologically interesting compounds via aza-conjugate addition of pyrimidine nucleobases to a,β-unsaturated esters in the presence of catalytic amount of LiOH.H2O (1.2-4.8 mol%) under microwave irradiation is described. This method affords the title compounds in good to excellent yields and i...
متن کاملAn Efficient and One-pot Procedure for the Synthesis of Chiral Isoxazolidine via Catalytic Highly Enantioselective 1,3-dipolar cycloaddition
Synthesis of enantiomerically pure isoxazolidine via an asymmetric 1,3- dipolar cycloaddition reaction of nitrone with electron-deficient dipolarophile was described. The process occurs at room temperature in aqueous ethanol as a green solvent and in the presence of a bidendate bis(imine)–Cu(II)triflate complex as catalyst. The reaction mechanism is discussed on the basis of the assignment of t...
متن کاملAsymmetric synthesis of chiral β-alkynyl carbonyl and sulfonyl derivatives via sequential palladium and copper catalysis† †Electronic supplementary information (ESI) available. See DOI: 10.1039/c6sc01724j Click here for additional data file.
We present a full account detailing the development of a sequential catalysis strategy for the synthesis of chiral b-alkynyl carbonyl and sulfonyl derivatives. A palladium-catalyzed cross coupling of terminal alkyne donors with acetylenic ester, ketone, and sulfone acceptors generates stereodefined enynes in high yield. These compounds are engaged in an unprecedented, regioand enantioselective ...
متن کاملAsymmetric synthesis of chiral β-alkynyl carbonyl and sulfonyl derivatives via sequential palladium and copper catalysis.
We present a full account detailing the development of a sequential catalysis strategy for the synthesis of chiral β-alkynyl carbonyl and sulfonyl derivatives. A palladium-catalyzed cross coupling of terminal alkyne donors with acetylenic ester, ketone, and sulfone acceptors generates stereodefined enynes in high yield. These compounds are engaged in an unprecedented, regio- and enantioselectiv...
متن کاملAsymmetric conjugate addition of arylthiols to enoates and its application to organic synthesis of biologically potent compounds.
As a part of our studies aimed at asymmetric catalytic reactions by using an external chiral ligand, we have developed a catalytic asymmetric addition reaction of an arylthiol to alpha,beta-unsaturated esters under the control of an external chiral ligand. The characteristic of our technology is a double activation of a thiol by lithiation and chelate formation with a chiral tridentate amino di...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- Angewandte Chemie
دوره 55 5 شماره
صفحات -
تاریخ انتشار 2016