doi:10.1002/chem.201601301engMéndez, IsabelRodríguez-Martínez, RicardoPolo, VíctorPassarelli, VicenzoLahoz, Fernando J.García-Orduña, PilarCarmona, DanielTemperature Dual Enantioselective Control in a Rhodium-Catalyzed Michael-Type Friedel-Crafts Reaction: A Mechanistic ExplanationART-2016-98884By changing the temperature from 283 to 233 K, the S (99% ee)orR (96 % ee)enantiomer of the Friedel–Crafts (FC) adduct of the reaction between N-methyl-2-methylindole and trans-b-nitrostyrene can be obtained by using (S Rh ,R C )-[(h 5 -C 5 Me 5 )Rh{(R)-Prophos}(H 2 O)][SbF 6 ] 2 as the catalyst precursor.This catalytic systempresents two otheruncom - mon features:1)The ee changes with reactio ntime showing trends that depend on the reactiontemperature and 2) an increase in the catalyst loading results in adecrease in the ee of the S enantiom er.Detection and characteriza tion of the intermediate metal-nitroalkene and metal–aci-nitro complexes, the free aci-nitro compound, and the FC adduct-complex, together with solution NMR measuremen ts, theo- retical calculations, and kinetic stu dies have allowed us to propose two plausible alternative catalytic cycles. On the basis of these cycles,all the above -mentioned observations can be rationalized. In particular,the reversibility of one of the cycles toget her with the kinetic resolution of the intermediate aci-nitro complexes accountfor the high ee values achieved in both antipodes.Onthe other hand, the results of kinetic measurements explain the unusual effect of the increment in catalyst loading.2016http://zaguan.unizar.es/record/8467010.1002/chem.201601301http://zaguan.unizar.es/record/84670oai:zaguan.unizar.es:84670info:eu-repo/grantAgreement/ES/MINECO/Consolider-Ingenio/CSD2006-0015info:eu-repo/grantAgreement/ES/MINECO/CTQ2012-32095info:eu-repo/grantAgreement/ES/MINECO/CTQ2015-66079-PChemistry - A European Journal 22, 31 (2016), 11064-11083All rights reservedhttp://www.europeana.eu/rights/rr-f/info:eu-repo/semantics/openAccess