SCHEDULED MAINTENANCE
Stereochemical significance of O to N atom interchanges within cationic helicenes: experimental and computational evidence of near racemization to remarkable enantiospecificity†
Geraldine M.
Labrador, 
a
Céline
Besnard,
b
Thomas
Bürgi,
c
Amalia I.
Poblador-Bahamonde,
*a
Johann
Bosson
*a
and
Jérôme
Lacour
*a
a
Céline
Besnard,
b
Thomas
Bürgi,
c
Amalia I.
Poblador-Bahamonde,
*a
Johann
Bosson
*a
and
Jérôme
Lacour
*a
Abstract
Oxygen atoms of cationic dioxa and azaoxa [6]helicenes can be exchanged by amino groups to form azaoxa and diaza [6]helicenes respectively. The mild reaction conditions developed herein allow the construction of libraries of derivatives with sensitive and/or functionalized side chains. Using enantioenriched dioxa or azaoxa helicene precursors, these exchanges lead to either near racemization (es 3%) or to a remarkable enantiospecificity (es up to 97%). This unusual behavior is fully characterized via experimental and computational mechanistic evidence. Based on these investigations, the enantiospecificity of the first transformation can be improved to 57–61%.
Please wait while we load your content...
