Efficient synthesis of chiral cyclic acetals by metal and Brønsted acid co-catalyzed enantioselective four-component cascade reactions.
نویسندگان
چکیده
Four-component Mannich reactions subsequently followed by an intramolecular oxo-Michael addition were developed to efficiently produce chiral cyclic acetals with high diastereoselectivity and enantioselectivity.
منابع مشابه
An enantioselective approach to 2,3-disubstituted indolines through consecutive Brønsted acid/Pd-complex-promoted tandem reactions.
Tandem reactions and consecutive catalysis (or relay catalysis) have been receiving considerable attention in organic synthesis due to their abilities of constructing multiple new chemical bonds to build complex chiral molecules in a single operation. Transition-metal-catalyzed asymmetric hydrogenation is one of the most widely used and reliable catalytic methods for preparation of chiral molec...
متن کاملA Highly Enantioselective Brønsted Acid Catalyzed Cascade Reaction: Organocatalytic Transfer Hydrogenation of Quinolines and their Application in the Synthesis of AlkaloidsThe authors acknowledge Degussa AG for generous funding
The enantioselective hydrogenation of olefins, ketones, and imines still represents an important topic in organic synthesis and catalysis. Although many highly enantioselective processes based on chiral Rh, Ru, and Ir complexes have been reported, most of these catalysts failed to give satisfactory results in the asymmetric hydrogenation of aromatic and heteroaromatic compounds. Examples of eff...
متن کاملHighly regio-, diastereo- and enantioselective one-pot gold/chiral Brønsted acid-catalysed cascade synthesis of bioactive diversely substituted tetrahydroquinolines.
One-pot sequential asymmetric reactions of aminobenzaldehydes or aminophenones with alkynes catalysed by a gold(I)/Brønsted acid cooperative system are reported. This process provides a highly efficient method for the synthesis of optically active tetrahydroquinolines, with one or two chiral centres at different positions as well as highly divergent functional groups, in good to excellent yield...
متن کاملFour-component Cascade Reaction was Programmed and Catalyzed by B(OH)3.H2O as an Efficient and Green Catalytic System
An aqueous solution of boric acid, as an efficient and green catalytic system, was efficiently utilized four-component cascade reaction of aryl aldehydes, dimedone, β-ketoesters and ammonium acetate to give hexahydroquinolines. By the reaction of boric acid with water, H+ was generated and efficiently catalyzed the reaction under mild and green condition. Also, optimization of the reaction cond...
متن کاملBrønsted Acid Catalyzed Phosphoramidic Acid Additions to Alkenes: Diastereo- and Enantioselective Halogenative Cyclizations for the Synthesis of C- and P-Chiral Phosphoramidates
The first highly diastereo- and enantioselective additions of a halogen and phosphoramidic acid to unactivated alkenes have been developed, catalyzed by a chiral Brønsted acid. A unique feature of these additions is the opportunity for stereocontrol at two noncontiguous chiral centers, carbon and phosphorus, leading to cyclic P-chiral phosphoramidates. In addition to their inherent value, the p...
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 50 17 شماره
صفحات -
تاریخ انتشار 2014