Liu, Kai; Yang, Jianfeng; Li, Xiaoxun published their research in Organic Letters in 2021. The article was titled 《Palladium-Catalyzed Diastereo- and Enantioselective [3 + 2] Cycloaddition of Vinylcyclopropanes with Azadienes: Efficient Access to Chiral Spirocycles》.Reference of 4-Methylbenzenesulfonamide The article contains the following contents:
The first palladium(0)-catalyzed diastereo- and enantioselective [3 + 2] annulation of vinylcyclopropanes (VCPs) I (R = methoxycarbonyl, (2,2,2-trifluoroethoxy)carbonyl, cyano) and BDAs II (R1 = Me, 4-methylphenyl, 4-bromophenyl; R2 = H, 6-Cl, 5-Br, 6-OMe; R3 = Ph, naphthalen-1-yl, thiophen-2-yl, etc.; X = C, O, S) and 2-(phenylmethylidene)-2,3-dihydro-1-benzothiophen-3-one were reported. This transformation is featured with a broad substrate scope III and IV, allowing for facile access to a variety of enantioenriched spirocycles bearing a quaternary stereogenic center in good yields with excellent regio-, diastereo-, and enantioselectivities (up to 93% yield, >20:1 dr, and mostly >99% ee) under mild reaction conditions. Moreover, the spirocyclic products III and IV could be efficiently converted to structurally complex tricyclo[8.3.0.01,5]-azatridecane and tricyclo[7.3.0.01,5]-azadodecane skeletons. The experimental part of the paper was very detailed, including the reaction process of 4-Methylbenzenesulfonamide(cas: 70-55-3Reference of 4-Methylbenzenesulfonamide)
4-Methylbenzenesulfonamide(cas: 70-55-3) belongs to anime. Primary amines having a tertiary alkyl group (R3CNH2) are difficult to prepare with most methods but are made industrially by the Ritter reaction. In this method a tertiary alcohol reacts with hydrogen cyanide (HCN) in the presence of a concentrated strong acid; a formamide, RNH―CHO, is formed first, which then undergoes hydrolysis.Reference of 4-Methylbenzenesulfonamide
Referemce:
Amide – Wikipedia,
Amide – an overview | ScienceDirect Topics