Open AccessAmine Protection/α-Activation with the tert-Butoxythiocarbonyl Group: Application to Azetidine Lithiation–Electrophilic Substitution
Author(s) -
David M. Hodgson,
Claire L. Mortimer,
Jeffrey M. McKenna
Publication year - 2014
Publication title -
organic letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.94
H-Index - 239
eISSN - 1523-7060
pISSN - 1523-7052
DOI - 10.1021/ol503441d
Subject(s) - azetidine , electrophile , chemistry , amine gas treating , adduct , ligand (biochemistry) , medicinal chemistry , group (periodic table) , stereochemistry , combinatorial chemistry , organic chemistry , catalysis , receptor , biochemistry
tert-Butoxythiocarbonyl (Botc), the long-neglected thiocarbonyl analogue of Boc, facilitates (unlike its alkoxycarbonyl cousin) α-lithiation and electrophile incorporation on N-Botc-azetidine. N,N,N',N'-endo,endo-Tetramethyl-2,5-diaminonorbornane proved optimal as a chiral ligand, generating adducts with er up to 92:8. Facile deprotection, under conditions that left the corresponding N-Boc systems intact, was achieved using either TFA or via thermolysis in ethanol.