Ninhydrin and heterocyclic ketene aminals (HKAs) are versatile building blocks in organic chemistry. Reactions of ninhydrin with HKAs initially produced the kinetic products indeno[1,2‐b]pyrrol‐4(1H)‐one derivatives, which could further isomerize to thermodynamic counterparts indeno[2,1‐b]pyrrol‐8(1H)‐ones. The isomerization showed a strong solvent dependency and occurred through a decomposition–reconstruction pathway. This is the first example of isomerization of ninhydrin‐constructed products. The conversion between kinetic and thermodynamic control may be applicable to similar reactions involving ninhydrin or HKAs.

No abstract

A method for preparation of 1,4,2-dithiazolidine or 1,3-thiazetidine heterocycles was developed by reactions of phenylthioureas with 1,1-dichloro-2-nitroethene. The solvent has a significant influence on the type of product formation. 1,4,2-Dithiazolidines were formed in the aprotic solvent chloroform, while in the protic solvent ethanol, 1,3-thiazetidines were the main products.

No abstract

No abstract