137393-98-7Relevant articles and documents
Preparation of (R)- and (S)-2-Alkyl-2-amino-3-(methylamino)propanoic and Other 2,3-Diaminoalkanoic Acid Derivatives from a Chiral Imidazoline
Pfammatter, Elmar,Seebach, Dieter
, p. 1323 - 1336 (2007/10/02)
t-Butyl 2-t-butyl-3-methyl-4-oxo-1-imidazolidinecarboxylate (Boc-BMI, 1) is deoxygenated (->3), reductively carboxylated (->10, 11), converted to an imidazolinedicarboxylate 31 and subjected to a 1,2-carbonyl-group transposition (->34).The new chiral building blocks thus obtained are used to synthesize derivatives of (i) 1,2-ethylenediamines (type 4-11), of diaminopropanols (8, 16-18) via the lithiated carbamate F, (ii) of 2-alkyl-2,3-diaminopropanoic acid (20-26, 30) via the enolate H, (iii) of higher 2,3-diaminoalkanoic acids (see 32, 33) via the Michael acceptor 31, and (iv) of simple α-(methylamino) acids (type 35) via the enolate of 34.A number of free α,β-diaminocarboxylic acids with a tertiary stereogenic center in the α-position is prepared (37 - 39).Some of these diamino acids are cyclized to β-lactams (41 - 43) bearing an alkyl and a phenylsulfonylamido group in the 2-position.Key Words: Imidazolidine, chiral, building block for amino acids / Ethylenediamines, enantioselective synthesis of / Carbamates, lithiated / Cuprate Michael additions / α,β-Diaminopropanoic acids, α-branched / β-Lactams / Amino acids
