Highly diastereo- and enantioselective construction of both central and axial chiralities by Rh-catalyzed [2 + 2 + 2] cycloaddition.
نویسندگان
چکیده
The cationic Rh-SEGPHOS complex catalyzed an intermolecular [2 + 2 + 2] cycloaddition of enynes, possessing an ortho-substituted aryl group on their alkyne terminus, with acetylenedicarboxylates. Bicyclic cyclohexa-1,3-dienes with both central and axial chiralities were obtained in extremely highly diastereo- and enantioselective manner.
منابع مشابه
Ir-catalyzed almost perfect enantioselective synthesis of helical polyaryls based on an axially-chiral sequence.
Ir-catalyzed enantioselective [2 + 2 + 2] cycloaddition of tetraynes or an octayne with monoalkynes proceeded to give helically-chiral quinquearyl and noviaryl compounds, which respectively have four and eight consecutive axial chiralities, in an almost enantiomerically pure form.
متن کاملConstruction of adjacent spiro-quaternary and tertiary stereocenters through phosphine-catalyzed asymmetric [3+2] annulation of allenoates with alkylidene azlactones.
A novel axially chiral spiro-phosphine-catalyzed highly regio-, diastereo- and enantioselective [3+2] cycloaddition of alkylidene azlactones with various allenic esters has been developed, affording the corresponding functionalized spirocyclic products in moderate to excellent yields under mild conditions. These spirocyclic products as masked amino acids can be easily transformed into aspartic ...
متن کاملThree-component procedure for the synthesis of new chiral spirooxindolopyrrolizidines via catalytic highly enantioselective 1,3-dipolar cycloaddition
The catalytic highly regio-, diastereo-, and enantioselective synthesis of a small library of spiropyrrolizidineoxindolesvia a four-component 1,3-dipolar cycloaddition reaction of azomethine ylides, derived from isatin, with electron-deficient dipolarophilewas described. The process occurs at room temperature in aqueous ethanol as a green solvent and in the presence of a bidendatebis(imine)–Cu(...
متن کاملChiral phosphoric acid catalyzed enantioselective 1,3-dipolar cycloaddition reaction of azlactones.
The first chiral phosphoric acid catalyzed highly diastereo- and enantioselective 1,3-dipolar cycloaddition reaction of azlactones and methyleneindolinones was disclosed. By using a BINOL-derived chiral phosphoric acid as the catalyst, azlactones were activated as chiral anti N-protonated 1,3-dipoles to react with methyleneindolinones to yield biologically important 3,3'-pyrrolidonyl spirooxind...
متن کاملThree-Component Procedure for the Synthesis Chiral Spirooxindolopyrrolizidines via Catalytic Highly Enantioselective 1,3-Dipolar Cycloaddition of Azomethineylides and 3-(2-Alkenoyl)-1,3-Oxazolidin-2-ones
The catalytic highly regio-, diastereo-, and enantioselective synthesis of a small library of spiropyrrolizidineoxindolesvia a four-component 1,3-dipolar cycloaddition reactionof azomethineylides, derived from isatin, with electron-deficient dipolarophilewas described. The process occurs at room temperature in aqueous ethanol as a green solvent and in the presence of a bidendatebis(imi...
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 6 23 شماره
صفحات -
تاریخ انتشار 2008