Premium
Frustrated Lewis Pair Chemistry of Chiral (+)‐Camphor‐Based Aminoboranes
Author(s) -
Lindqvist Markus,
Axenov Kirill,
Nieger Martin,
Räisänen Minna,
Leskelä Markku,
Repo Timo
Publication year - 2013
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.201300462
Subject(s) - iminium , chemistry , adduct , enamine , frustrated lewis pair , borane , catalysis , salt (chemistry) , intermolecular force , medicinal chemistry , lewis acids and bases , stereochemistry , molecule , organic chemistry
Dimethylamino‐(+)‐camphorenamine reacted with an equimolar amount of Piers’ borane, HB(C 6 F 5 ) 2 , to give the corresponding iminium–hydroborate zwitterionic salt. Being in equilibrium with the parent enamine–HB(C 6 F 5 ) 2 N–B pair, this salt was able to split hydrogen heterolytically, hydrogenating the iminium group in the molecule. Detailed studies revealed that the hydrogen splitting in this reaction proceeded through an intermolecular pathway leading to a bornylamine–HB(C 6 F 5 ) 2 adduct. When the starting enamine is present in excess over HB(C 6 F 5 ) 2 , the produced bornylamine–HB(C 6 F 5 ) 2 adduct breaks up, eliminating free bornylamine and forming the initial camphorenamine– HB(C 6 F 5 ) 2 pair. This results in hydrogenation of the camphorenamine framework in a catalytic fashion.