Dimerization and isomerization reactions of alpha-lithiated terminal aziridines.
The scope of dimerization and isomerization reactions of alpha-lithiated terminal aziridines is detailed. Regio- and stereoselective deprotonation of simple terminal aziridines with lithium 2,2,6,6-tetramethylpiperidide (LTMP) or lithium dicyclohexylamide (LiNCy2) generates trans-alpha-lithiated terminal aziridines. These latter species can then undergo dimerization or isomerization reactions depending on the nature of the N-protecting group. alpha-Lithiated terminal aziridines bearing N-alkoxycarbonyl (Boc) protection undergo N- to C-[1,2] migration to give N-H trans-aziridinylesters. In contrast, aziridines bearing N-organosulfonyl [tert-butylsulfonyl (Bus)] protection undergo rapid dimerization to give 2-ene-1,4-diamines or, if a pendant alkene is present, diastereoselective cyclopropanation to give 2-aminobicyclo[3.1.0]hexanes. All of these reactions were used as key steps in the preparation of synthetically and biologically important targets.
Hodgson
David M
DM
Department of Chemistry, University of Oxford, Chemistry Research Laboratory, Mansfield Road, Oxford, OX1 3TA, United Kingdom. david.hodgson@chem.ox.ac.uk
Humphreys
Philip G
PG
Miles
Steven M
SM
Brierley
Christopher A J
CA
Ward
John G
JG
D000588:Amines / Q000138:chemical synthesis / Q000737:chemistry; D001388:Aziridines / Q000737:chemistry*; D003521:Cyclopropanes / Q000138:chemical synthesis; D019281:Dimerization; D004952:Esters / Q000138:chemical synthesis / Q000737:chemistry; D008094:Lithium / Q000737:chemistry*; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism
D000588:Amines; D001388:Aziridines; D003521:Cyclopropanes; D004952:Esters; D009942:Organometallic Compounds; D008094:Lithium