DABCO-catalyzed regioselective cyclization reactions of β,γ-unsaturated α-ketophosphonates or β,γ-unsaturated α-ketoesters with allenic esters.
نویسندگان
چکیده
Highly efficient DABCO-catalyzed [4 + 2] cycloaddition of β,γ-unsaturated α-ketophosphonates or β,γ-unsaturated α-ketoesters with allenic esters gives the corresponding highly functionalized tetrahydropyran and dihydropyran derivatives in good to excellent yields and moderate to good regioselectivities under mild conditions.
منابع مشابه
Synthesis of optically active dihydropyrans from asymmetric [4 + 2] cycloaddition of β,γ-unsaturated α-ketoesters with allenic esters.
β-Isocupreidine (β-ICD) catalyzed asymmetric [4 + 2] cycloaddition of β,γ-unsaturated α-ketoesters with allenic esters afforded ester-substituted functionalized dihydropyran derivatives in high yields along with high enantioselectivities under mild conditions.
متن کاملTriphenylphosphine oxide-catalyzed stereoselective poly- and dibromination of unsaturated compounds.
A novel PPh3O catalyzed bromophosphonium salt-mediated dibromination of α,β-unsaturated esters and β,γ-unsaturated α-ketoesters has been developed. The products were obtained with good to excellent yields and excellent diastereoselectivities. This dibromination reaction is a good complement to the field of dibromination.
متن کاملPhosphine-catalyzed highly diastereoselective [3+2] cyclization of isatin derived electron-deficient alkenes with α-allenic esters.
A novel phosphine-catalyzed highly diastereoselective [3+2] cycloaddition of isatin derived α,β-unsaturated ketones with α-allenic ester has been developed.
متن کاملα-Ketophosphonates as ester surrogates: isothiourea-catalyzed asymmetric diester and lactone synthesis.
Isothiourea HBTM-2.1 catalyzes the asymmetric Michael addition/lactonization of aryl- and alkenylacetic acids using α-keto-β,γ-unsaturated phosphonates as α,β-unsaturated ester surrogates, giving access to a diverse range of stereodefined lactones or enantioenriched functionalized diesters upon ring-opening.
متن کاملEnantioselective γ-Alkylation of α,β-Unsaturated Malonates and Ketoesters by a Sequential Ir-Catalyzed Asymmetric Allylic Alkylation/Cope Rearrangement.
A catalytic, enantioselective γ-alkylation of α,β-unsaturated malonates and ketoesters is reported. This strategy entails a highly regio- and enantioselective iridium-catalyzed α-alkylation of an extended enolate, and a subsequent translocation of chirality to the γ-position via a Cope rearrangement.
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 10 1 شماره
صفحات -
تاریخ انتشار 2012