1174640-63-1Relevant academic research and scientific papers
DBU-catalyzed addition reactions of sulfonylimidates
Matsubara, Ryosuke,Kobayashi, Shu
, p. 3009 - 3011 (2008)
Sulfonylimidates react with various types of N-protected imines in the presence of a catalytic amount of DBU to afford β-aminosulfonylimidates in high yields and high anti-selectivities. The experimental procedure is described in detail. Georg Thieme Verlag Stuttgart.
Catalytic Mannich-type reactions of Sulfonylimidates
Matsubara, Ryosuke,Berthiol, Florian,Nguyen, Huy V.,Kobayashi, Shu
experimental part, p. 1083 - 1102 (2009/12/25)
A novel nucleophile, sulfonylimidate, has been successfully employed in Mannich-type reactions. Due to electronwithdrawing property of sulfonyl group of sulfonylimidate, the acidity of α-proton is enhanced so that sulfonylimidate bearing no activating functional group at α-position is deprotonated by relatively weak base. DBU-catalyzed reactions of sulfonylimidates with protected imines in DMF provided the adducts in high yields with high anti selectivity. This reaction represents a wide substrate scope and a high catalytic turnover. A thorough kinetic study revealed that ratedetermining step is most likely deprotonation step in case of Ts-imidate. Alkali earth metal alkoxide and its HMDS salt also catalyze Mannich-type reactions of sulfonylimidates. The reactions catalyzed by Mg(O tBu)2 in DMF provided the adducts with high anti selectivity, while those catalyzed by [Sr(HMDS)2]2 gave syn selectivity. The asymmetric variant of Mannich-type reaction of sulfonylimidate was also achieved. Several transformations of sulfonylimidates to other functional groups were also demonstrated. Finally, direct-type catalytic formation of cβ-amino acid ester from aldehyde and sulfonylimidate was achieved via in situ formation of sulfonylimine and DBU-assisted hydrolysis of sulfonylimidate.
