Regio- and enantioselective synthesis of N-substituted pyrazoles by rhodium-catalyzed asymmetric addition to allenes.
The rhodium-catalyzed asymmetric N-selective coupling of pyrazole derivatives with terminal allenes gives access to enantioenriched secondary and tertiary allylic pyrazoles, which can be employed for the synthesis of medicinally important targets. The reaction tolerates a large variety of functional groups and labelling experiments gave insights into the reaction mechanism. This new methodology was further applied in a highly efficient synthesis of JAK 1/2 inhibitor (R)-ruxolitinib.
Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg im Breisgau (Germany).
Alexander M
AM
Haydl
Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg im Breisgau (Germany).
Kun
K
Xu
Institut für Organische Chemie, Albert-Ludwigs-Universität Freiburg, Albertstrasse 21, 79104 Freiburg im Breisgau (Germany). bernhard.breit@chemie.uni-freiburg.de.
Bernhard
B
Breit
D000466:Alkadienes / Q000737:chemistry*; D002384:Catalysis; D009570:Nitriles; D009584:Nitrogen / Q000737:chemistry; D011720:Pyrazoles / Q000138:chemical synthesis / Q000737:chemistry*; D011743:Pyrimidines; D012238:Rhodium / Q000737:chemistry*; D013237:Stereoisomerism
D000466:Alkadienes; D009570:Nitriles; D011720:Pyrazoles; D011743:Pyrimidines; C031280:pyrazole; C025947:propadiene; C540383:ruxolitinib; D012238:Rhodium; D009584:Nitrogen
allenes; allylic compounds; asymmetric catalysis; heterocycles; rhodium