212195-36-3Relevant academic research and scientific papers
Asymmetric synthesis of α-substituted N-methylsulfonamides
Enders, Dieter,Thomas, Christian R.,Vignola, Nicola,Raabe, Gerhard
, p. 3657 - 3677 (2007/10/03)
A novel amine auxiliary for the asymmetric synthesis of α-substituted N-methylsulfonamides is described. The reaction of 4-([1,1′-biphenyl]-4-yl)-2,2-dimethyl-1,3-dioxan-5-amine (16) with various aliphatic sulfonyl chlorides afforded the corresponding sulfonamides, which were lithiated and subsequently reacted with electrophiles to give the corresponding products in high yields and good-to-excellent asymmetric inductions (de 83-95%). Racemization-free cleavage of the auxiliary led to the α-alkylated N-methylsulfonamides in acceptable yields and high enantiomer purities (ee 91 to ≥ 98).
Enantioselective synthesis of α-substituted N-methyl-sulfonamides
Enders, Von Dieter,Thomas, Christian R.,Raabe, Gerhard,Runsink, Jan
, p. 1329 - 1336 (2007/10/03)
The first asymmetric α-alkylations of lithiated sulfonamides bearing the chirality information within the amine moiety under high asymmetric inductions (de 83-95 %) are described. Racemization-free acidic hydrolysis led to the title compounds 11 in acceptable overall yields and with high enantiomeric purity (ee 91- ≤98%; Scheme 2). As a novel chiral auxiliary, the primary amine (S,S)- or (R,R)-2 was synthesized employing the classical Erlenmeyer phenylserine synthesis (Schone I).
