3979-67-7Relevant articles and documents
A hydrogen borrowing annulation strategy for the stereocontrolled synthesis of saturated aza-heterocycles
Armstrong, Roly J.,Chamberlain, Anna E. R.,Donohoe, Timothy J.,Paterson, Kieran J.,Twin, Heather C.
supporting information, p. 3563 - 3566 (2020/04/03)
An iridium catalyzed method for the synthesis of saturated aza-heterocycles from amines and diols is reported. A wide range of substituted heterocycles can be obtained using this approach including products bearing substituents at the C2, C3 and C4 positions. Employing water as the solvent, enantiopure diols could undergo annulation with minimal racemization, enabling the synthesis of valuable enantioenriched C3 and C4-substituted saturated aza-heterocycles.
Asymmetric Hydrogenation of 3-Substituted Pyridinium Salts
Renom-Carrasco, Marc,Gajewski, Piotr,Pignataro, Luca,de Vries, Johannes G.,Piarulli, Umberto,Gennari, Cesare,Lefort, Laurent
, p. 9528 - 9532 (2016/07/14)
The use of an equivalent amount of an organic base leads to high enantiomeric excess in the asymmetric hydrogenation of N-benzylated 3-substituted pyridinium salts into the corresponding piperidines. Indeed, in the presence of Et3N, a Rh-JosiPhos catalyst reduced a range of pyridinium salts with ee values up to 90 %. The role of the base was elucidated with a mechanistic study involving the isolation of the various reaction intermediates and isotopic labeling experiments. Additionally, this study provided some evidence for an enantiodetermining step involving a dihydropyridine intermediate.
