Preparation of diamines by lithiation-substitution of imidazolidines and pyrimidines.
The synthesis of chiral 1,2-diamines and 1,3-diamines was achieved from the unsubstituted diamines by way of N-tert-butoxycarbonyl (Boc) substituted imidazolidines (tetrahydroimidazoles) and pyrimidines (hexahydro-1,3-diazines), which were treated with sec-butyllithium to effect deprotonation alpha- to the N-Boc group, followed by addition of an electrophile to give substituted products that could be hydrolysed under acidic conditions to give the substituted 1,2- or 1,3-diamines. Use of the chiral ligand (-)-sparteine promoted asymmetric deprotonation of the imidazolidine substrates to give, after hydrolysis, enantiomerically enriched 1,2-diamines.
Ashweek
Neil J
NJ
School of Chemistry, University of Exeter, Stocker Road, Exeter, UK EX4 4QD.
Coldham
Iain
I
Haxell
Thomas F
TF
Howard
Steven
S
D003959:Diamines / Q000138:chemical synthesis*; D007093:Imidazoles / Q000737:chemistry*; D011743:Pyrimidines / Q000737:chemistry*
D003959:Diamines; D007093:Imidazoles; D011743:Pyrimidines