Synthesis and Applications of the C2-Symmetrical Diamine 2,7-Diazabicyclo[4.4.1]undecane

J Org Chem. 2020 Jun 5;85(11):7424-7432. doi: 10.1021/acs.joc.0c00829. Epub 2020 May 13.

Abstract

Chiral diamines are particularly useful as ligands for asymmetric catalysis. In an effort to expand the library of such diamines, the synthesis and resolution of the C2-symmetric diamine 2,7-diazabicyclo[4.4.1]undecane [(-)-1] are reported. Diamine (-)-1 has been prepared in multigram quantities from the known bicyclic diketone 7 in four steps without the need for chromatographic purification. Derivatives of (-)-1, i.e., the bis-methylated diamine (+)-5 and two diastereomeric tricyclic analogs, were evaluated as potential sparteine surrogates. The solid-state structure of the (+)-5-methyllithium complex was obtained. High levels of asymmetric induction were observed while using (+)-5 as a ligand in palladium-mediated asymmetric allylations.