1492905-77-7Relevant academic research and scientific papers
C2-Symmetric hemiaminal ethers and diamines: New ligands for copper-catalyzed desymmetrization of meso-1,2-diols and asymmetric Henry reactions
Kaluza, Zbigniew,Bielawski, Krzysztof,Cwiek, Rafal,Niedziejko, Piotr,Kaliski, Przemyslaw
, p. 1435 - 1442 (2013)
The synthesis of novel, enantiomerically pure C2-symmetrical hemiaminal ethers and diamines containing piperazine core is presented. The key steps of the synthesis involve the dimerization of an in situ generated α-amino aldehyde into the corresponding cyclic bis-hemiaminal, followed by dehydration in the presence of a base to give a 7-oxa-2,5-diaza-bicyclo[2.2.1] heptane derivative, which can be regarded as a bicyclic bis-hemiaminal inner ether. These compounds represent a new class of molecule, with a structure unambiguously established for the first time. Finally, sodium triacetoxy-borohydride reduction gave the corresponding diamines. Both classes of compounds, new diamines and hemiaminal ethers, were shown to be good ligands for the copper(II)-catalyzed desymmetrization of meso-diols (up to 87% ee) and Henry reactions (up to 84% ee).
