The complete characterization of a rhodium Lewis acid-dipolarophile complex as an intermediate for the enantioselective catalytic 1,3-dipolar cycloaddition of C,N-diphenylnitrone to methacrolein.
The 1,3-dipolar cycloaddition reaction of C,N-diphenylnitrone with methacrolein is efficiently catalyzed by the rhodium diphosphine compound (SRh,RC)-[(eta5-C5Me5)Rh(R-Prophos)(H2O)](SbF6)2 [R-Prophos = (R)-(+)-1,2-bis(diphenylphosphino)-propane, 1.SbF6]; the asymmetric catalytic process occurs with reversal of regioselectivity, perfect endo selectivity, and up to 92% ee. The complete (NMR and X-ray analysis) characterization of the involved intermediate (SRh,RC)-[(eta5-C5Me5)Rh(R-Prophos)(methacrolein)](SbF6)2 (7.SbF6) allows us to interpret the observed selectivity.
Departamento de Química Inorgánica, Instituto de Ciencia de Materiales de Aragón, Universidad de Zaragoza-Consejo Superior de Investigaciones Científicas, 50009 Zaragoza, Spain. dcarmona@unizar.es
Daniel
D
Carmona
M Pilar
MP
Lamata
Fernando
F
Viguri
Ricardo
R
Rodríguez
Luis A
LA
Oro
Ana I
AI
Balana
Fernando J
FJ
Lahoz
Tomás
T
Tejero
Pedro
P
Merino
Santiago
S
Franco
Isabel
I
Montesa
D000171:Acrolein / Q000737:chemistry*; D000475:Alkenes / Q000737:chemistry*; D002384:Catalysis; D003500:Cyclization; D007555:Isoxazoles / Q000138:chemical synthesis*; D009589:Nitrogen Oxides / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D012238:Rhodium / Q000737:chemistry*; D013237:Stereoisomerism; D014961:X-Ray Diffraction
D000475:Alkenes; D007555:Isoxazoles; D009589:Nitrogen Oxides; D009942:Organometallic Compounds; C015388:nitrones; D000171:Acrolein; D012238:Rhodium