Readily available tetrachloro-2-aza-1,3-butadienes enter into directed cyclocondensation reaction with N-phenyl-1,2-cyclopentanediamine which leads to regioselective cyclopentane annulation by the 1,3,5-triazepine. The formation of the 1,3,5-triazepine derivatives was confirmed proved by 1H- and 13C-NMR spectral study, elemental analysis and, in one case, single-crystal x-ray crystallographic study.
This paper summarizes the reaction of DABCO with the enol tosylate derivatives made from (L-Ser-L-Ser) and (L-Phe-L-Ser) diketopiperazines (DKP’s). The reaction between DABCO and EE-di-tosylate (L-Ser-L-Ser) DKP (2), results in the isomerization of the serine di-tosylate from EE-2 to ZZ-2. This is the first direct example of the utility of DABCO as a reagent demonstrating the successful isomerization in a DKP derivative. The E-enol tosylate of (L-Phe-L-Ser) DKP (4) upon reaction with DABCO provided a unique bis-ylidiene product (5).
A bronsted acid-surfactant catalysed and simple, mild, metal catalyst free and chemo-selective method has been developed for synthesis of 1, 3, 5-triaryl benzenes from aryl methyl ketones. The advantages of this protocol subsume green and sustainable reaction medium, mild reaction conditions, easy product recovery and its good yields.