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The Origin of Anti‐Markovnikov Regioselectivity in Alkene Hydroamination Reactions Catalyzed by [Rh(DPEphos)] +
Author(s) -
CouceRios Almudena,
Lledós Agustí,
Ujaque Gregori
Publication year - 2016
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201504645
Subject(s) - regioselectivity , hydroamination , markovnikov's rule , alkene , chemistry , nucleophile , amination , medicinal chemistry , reductive elimination , catalysis , combinatorial chemistry , organic chemistry
The development of regioselective anti‐Markovnikov alkene's hydroamination is a long‐standing goal in catalysis. The [Rh(COD)(DPEphos)] + complex is the most general and regioselective group 9 catalyst for such a process. The reaction mechanism for intermolecular hydroamination of alkenes catalyzed by [Rh(DPEphos)] + complex is analyzed by means of DFT calculations. Hydroamination (alkene vs. amine activation routes) as well as oxidative amination pathways are analyzed. According to the computational results the operating mechanism can be generally described by alkene coordination, amine nucleophilic addition, proton transfer through the metal center and reductive elimination steps. The mechanism for the formation of the oxidative amination side product goes via a β‐elimination after the nucleophilic addition and metal center protonation steps. The origin of the regioselectivity for the addition process (Markovnikov vs. anti‐Markovnikov additions) is shown to be not charge but orbitally driven. Remarkably, η 2 to η 1 slippage degree on the alkene coordination mode is directly related to the regioselective outcome.