title: Combining silver- and organocatalysis: an enantioselective sequential catalytic approach towards pyrano-annulated pyrazoles.
abstract: A one-pot asymmetric Michael addition/hydroalkoxylation sequence, catalyzed by a sequential catalytic system consisting of a squaramide and a silver salt, provides a new series of chiral pyrano-annulated pyrazole derivatives in excellent yields (up to 95%) and high enantioselectivities (up to 97% ee).
authors.affiliation: Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany. enders@rwth-aachen.de.
authors.forename: Daniel
authors.initials: D
authors.lastname: Hack
authors.forename: Pankaj
authors.initials: P
authors.lastname: Chauhan
authors.forename: Kristina
authors.initials: K
authors.lastname: Deckers
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Mizutani
authors.forename: Gerhard
authors.initials: G
authors.lastname: Raabe
authors.forename: Dieter
authors.initials: D
authors.lastname: Enders
mesh_terms: D002384:Catalysis; D018360:Crystallography, X-Ray; D003500:Cyclization; D008968:Molecular Conformation; D011720:Pyrazoles / Q000138:chemical synthesis / Q000737:chemistry*; D012834:Silver / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D011720:Pyrazoles; D012834:Silver; C031280:pyrazole