Arylhydroxylamines were used in the nitroso Diels-Alder reaction to generate in-situ nitrosoarens under visible light catalytic aerobic conditions. Mixing a solution of aryl- or heteroaryl-hydroxylamines with conjuguated dienes in the presence of a catalytic amount of Ru(bpy)3Cl2 afforded, under an oxygen atmosphere, the 3,6-dihydro-1,2-oxazines in good yields.
Molecular Design of a Chiral Brønsted 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
A chiral Brønsted 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
An efficient enantioselective construction of tetrahydronaphthalene-1,4-diones as well as dihydronaphthalene-1,4-diols by a chiral phosphoric acid catalyzed quinone Diels-Alderreaction with dienecarbamates is reported. The nature of the protecting group on the diene is key to the success of achieving high enantioselectivity. The divergent "redox" selectivity is controlled by using an adequate amount
Regio-, Diastereo-, and Enantioselective Nitroso-Diels–Alder Reaction of 1,3-Diene-1-carbamates Catalyzed by Chiral Phosphoric Acids
作者:Jonathan Pous、Thibaut Courant、Guillaume Bernadat、Bogdan I. Iorga、Florent Blanchard、Géraldine Masson
DOI:10.1021/jacs.5b08515
日期:2015.9.23
nitroso-Diels-Alder reaction of nitrosoarenes with carbamate-dienes afforded cis-3,6-disubstituted dihydro-1,2-oxazines in high yields with excellent regio-, diastereo-, and enantioselectivities. Interestingly, we observed that the catalyst is able not only to control the enantioselectivity but also to reverse the regioselectivity of the noncatalyzed nitroso-Diels-Alder reaction. The regiochemistryreversal and asynchronous