Mechanistic Dichotomy in the Asymmetric Allylation of Aldehydes with Allyltrichlorosilanes Catalyzed by Chiral Pyridine N-Oxides

0398752 - ÚOCHB 2014 RIV DE eng J - Článek v odborném periodiku
Malkov, A. V. - Stončius, S. - Bell, M. - Castelluzzo, F. - Ramírez-López, P. - Biedermannová, Lada - Langer, V. - Rulíšek, Lubomír - Kočovský, P.
Mechanistic Dichotomy in the Asymmetric Allylation of Aldehydes with Allyltrichlorosilanes Catalyzed by Chiral Pyridine N-Oxides.
Chemistry - A European Journal. Roč. 19, č. 28 (2013), s. 9167-9185. ISSN 0947-6539. E-ISSN 1521-3765
Grant CEP: GA MŠMT LC512
Institucionální podpora: RVO:61388963 ; RVO:86652036
Klíčová slova: allylation * allylsilanes * calculations * organocatalysis * pyridine N-oxides
Kód oboru RIV: CF - Fyzikální chemie a teoretická chemie
Impakt faktor: 5.696, rok: 2013

Detailed kinetic and computational investigation of the enantio- and diastereoselective allylation of aldehydes 1 with allyltrichlorosilanes 5, employing the pyridine N-oxides METHOX (9) and QUINOX (10) as chiral organocatalysts, indicate that the reaction can proceed through a dissociative (cationic) or associative (neutral) mechanism: METHOX apparently favors a pentacoordinate cationic transition state, while the less sterically demanding QUINOX is likely to operate via a hexacoordinate neutral complex. In both pathways, only one molecule of the catalyst is involved in the rate- and selectivity-determining step, which is supported by both experimental and computational data.
Trvalý link: http://hdl.handle.net/11104/0226239