A Chiral Thiourea as a Template for Enantioselective Intramolecular [2 + 2] Photocycloaddition Reactions.
A chiral (1R,2R)-diaminocyclohexane-derived bisthiourea was found to exhibit a significant asymmetric induction in the intramolecular [2 + 2] photocycloaddition of 2,3-dihydropyridone-5-carboxylates. Under optimized conditions, the reaction was performed with visible light employing 10 mol % of thioxanthone as triplet sensitizer. Due to the different electronic properties of its carbonyl oxygen atoms, a directed binding of the substrate to the template is possible, which in turn enables an efficient enantioface differentiation.
Department Chemie and Catalysis Research Center (CRC), Technische Universität München , Lichtenbergstrasse 4, 85747 Garching, Germany.
Florian
F
Mayr
Department Chemie and Catalysis Research Center (CRC), Technische Universität München , Lichtenbergstrasse 4, 85747 Garching, Germany.
Richard
R
Brimioulle
Department Chemie and Catalysis Research Center (CRC), Technische Universität München , Lichtenbergstrasse 4, 85747 Garching, Germany.
Thorsten
T
Bach