Amidation of silyl enol ethers and cholesteryl acetates with chiral ruthenium(II) schiff-base catalysts: catalytic and enantioselective studies.

نویسندگان

  • Jiang-Lin Liang
  • Xiao-Qi Yu
  • Chi-Ming Che
چکیده

Chiral ruthenium(II)-salen complexes [RuII(salen)(PPh3)2] catalyse asymmetric aziridination of alkenes with up to 83% ees, asymmetric amidation of silyl enol ethers with up to 97% ees, and allylic amidation of cholesteryl acetates with good regioselectivity.

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

Catalytic, Enantioselective Sulfenylation of Ketone-Derived Enoxysilanes

A catalytic, enantioselective, Lewis base-catalyzed α-sulfenylation of silyl enol ethers has been developed. To avoid acidic hydrolysis of the silyl enol ether substrates, a sulfenylating agent that did not require additional Brønsted acid activation, namely N-phenylthiosaccharin, was developed. Three classes of Lewis bases-tertiary amines, sulfides, and selenophosphoramides-were identified as ...

متن کامل

Chiral Brønsted acid from a cationic gold(I) complex: catalytic enantioselective protonation of silyl enol ethers of ketones.

A chiral Brønsted acid has been developed from a cationic gold(I) disphosphine complex in the presence of alcoholic solvent and applied to the enantioselective protonation reaction of silyl enol ethers of ketones. Various optically active cyclic ketones were obtained in excellent yields and high enantioselectivities, including cyclic ketones bearing aliphatic substrates at the α-position. Furth...

متن کامل

Highly enantioselective Mukaiyama aldol reaction in aqueous conditions using a chiral iron(II) bipyridine catalyst.

A highly enantioselective method for the catalytic Mukaiyama aldol reaction of silyl enol ethers with aldehydes in aqueous conditions was developed. The desired aldol products were obtained in excellent yields, diastereo- and enantioselectivities. Structural evidence of the pre-catalyst revealed an unprecedented heptadentate Fe(II) complex with the chiral bipyridine ligand.

متن کامل

Ruthenium-catalyzed regio- and enantioselective allylic substitution with water: direct synthesis of chiral allylic alcohols.

Enantioselective allylic substitution catalyzed by transitionmetal complexes is an important process in organic synthesis. For many years, mainly palladium complexes that contain chiral ligands have been employed as efficient catalysts in these reactions. Recent studies have demonstrated that chiral catalysts based on other transition metals show different regioselectivity in the synthesis of b...

متن کامل

Synthesis and Metal Ion Uptake Studies of Silica Gel-Immobilized Schiff Base Derivatives and Catalytic Behaviors of their Cu(II) Complexes

New silica supported Schiff base ligands were prepared by the condensation reaction of 4,6-diacetylresorcinol with silica-gel derivatives, which modified with 3-aminopropyltriethoxysilane and N-(2-aminoethyl) -3-aminopropyltrimethoxysilane. Metal ion uptake capacities of these compounds were studied towards of selected transition metal (Cd(II), Cu(II), Co(II), Mn(II), Pb(II) and Ni(II)) cations...

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:
  • Chemical communications

دوره 2  شماره 

صفحات  -

تاریخ انتشار 2002