65899-50-5Relevant articles and documents
Molecular Design of a Chiral Br?nsted Acid with Two Different Acidic Sites: Regio-, Diastereo-, and Enantioselective Hetero-Diels-Alder Reaction of Azopyridinecarboxylate with Amidodienes Catalyzed by Chiral Carboxylic Acid-Monophosphoric Acid
Momiyama, Norie,Tabuse, Hideaki,Noda, Hirofumi,Yamanaka, Masahiro,Fujinami, Takeshi,Yamanishi, Katsunori,Izumiseki, Atsuto,Funayama, Kosuke,Egawa, Fuyuki,Okada, Shino,Adachi, Hiroaki,Terada, Masahiro
supporting information, p. 11353 - 11359 (2016/10/12)
A chiral Br?nsted acid containing two different acidic sites, chiral carboxylic acid-monophosphoric acid 1a, was designed to be a new and effective concept in catalytic asymmetric hetero-Diels-Alder reactions of azopyridinecarboxylate with amidodienes. The multipoint hydrogen-bonding interactions among the carboxylic acid, monophosphoric acid, azopyridinecarboxylate, and amidodiene achieved high catalytic and chiral efficiency, producing substituted 1,2,3,6-tetrahydropyridazines with excellent stereocontrol in a single step. This constitutes the first example of regio-, diastereo-, and enantioselective azo-hetero-Diels-Alder reactions by chiral Br?nsted acid catalysis.
Catalytic Asymmetric Diels-Alder Reaction of Quinone Imine Ketals: A Site-Divergent Approach
Hashimoto, Takuya,Nakatsu, Hiroki,Maruoka, Keiji
supporting information, p. 4617 - 4621 (2015/04/14)
The catalytic asymmetric Diels-Alder reaction of quinone imine ketals with diene carbamates catalyzed by axially chiral dicarboxylic acids is reported herein. A variety of primary and secondary alkyl-substituted quinone derivatives which have not been applied in previous asymmetric quinone Diels-Alder reactions could be employed using this method. More importantly, we succeeded in developing a strategy to divert the reaction site in unsymmetrical 3-alkyl quinone imine ketals from the inherently favored unsubstituted C=C bond to the disfavored alkyl-substituted C=C bond.
