Premium
Early Main Group Metal Catalysis: How Important is the Metal?
Author(s) -
Penafiel Johanne,
Maron Laurent,
Harder Sjoerd
Publication year - 2015
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201408814
Subject(s) - hydroamination , alkene , intramolecular force , catalysis , chemistry , medicinal chemistry , metal , polymer chemistry , photochemistry , organic chemistry
Organocalcium compounds have been reported as efficient catalysts for various alkene transformations. In contrast to transition metal catalysis, the alkenes are not activated by metal–alkene orbital interactions. Instead it is proposed that alkene activation proceeds through an electrostatic interaction with a Lewis acidic Ca 2+ . The role of the metal was evaluated by a study using the metal‐free catalysts: [Ph 2 N − ][Me 4 N + ] and [Ph 3 C − ][Me 4 N + ]. These “naked” amides and carbanions can act as catalysts in the conversion of activated double bonds (CO and CN) in the hydroamination of ArNCO and RNCNR (R=alkyl) by Ph 2 NH. For the intramolecular hydroamination of unactivated CC bonds in H 2 CCHCH 2 CPh 2 CH 2 NH 2 the presence of a metal cation is crucial. A new type of hybrid catalyst consisting of a strong organic Schwesinger base and a simple metal salt can act as catalyst for the intramolecular alkene hydroamination. The influence of the cation in catalysis is further evaluated by a DFT study.