89598-08-3Relevant academic research and scientific papers
Asymmetric synthesis of α-substituted N-methylsulfonamides
Enders, Dieter,Thomas, Christian R.,Vignola, Nicola,Raabe, Gerhard
, p. 3657 - 3677 (2002)
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).
Asymmetric Diels-Alder Reactions with Sulfines Derived from Proline
Broek, Leon A. G. M. van den,Porskamp, Pascal A. T. W.,Haltiwanger, R. Curtis,Zwanenburg, Binne
, p. 1691 - 1695 (2007/10/02)
The Synthesis of a variety of sulfines 8 derived from S-proline, utilizing the reaction of α-silyl carbanions with sulfur dioxide, is described.Reaction of the thus prepared sulfines 8 with 2,3-dimethyl-1,3-butadiene gave dihydrothiopyran S-oxides 9.During these cycloaddition reactions asymmetric inductions up to 40percent were observed.From one pure diastereomeric form of cycloadduct 9d an X-ray analysis was carried out in order to provide insight in the steric course of the cycloaddition reaction.
