Conquering amide planarity: Structural distortion and its hidden reactivity

Amides are generally considered as a low-reactive chemical entity among the carbonyl group, and therefore fewer opportunities to be involved in catalytic transformations as substrates. The origin of the stable nature of amides is resonance stabilization in the planar structure, which has drawn considerable attention from organic and physical chemists, leading to the discovery of distorted amides that exhibit a substantially reactive nature. Recent focus in this field is on the catalytic transformation of designed amides with moderate distortion or reduced resonance stabilization. This digest reviews the brief history of the quest for highly distorted amides and introduces a collection of recent studies on catalytic transformations of designed amides.     

A new method using 1,3,5-triazine as an umpolung hydrogen cyanide equivalent toward the syntheses of isoquinolinone and 2-pyridone derivatives

An investigation of Hermecz and Hartenstein’s cyclization methods was conducted. Overcoming the limited substrate scope allowed the expansion of the synthetic application of 1,3,5-triazine as an umpolung hydrogen cyanide equivalent. The reaction proceeded under mild conditions to provide various isoquinolinone and 2-pyridone derivatives with excellent yields.     

Photon Trapping and the Enhancement of Electronic Excitation Energy Transfer Efficiency Caused by Colloidal Crystals

Summary: The efficiency of electronic excitation energy transfer from photoexcited fluorescein to rhodamine 6G is enhanced by 2.26 times in an exhaustively deionized colloidal silica suspension. This enhancement is caused by the photon trapping effects due to the Bragg reflection of colloidal crystals formed in the suspension. The lower enhancement efficiency of 1.41 times observed for rhodamine B as an acceptor is attributed to the inefficient spectral overlap between donor fluorescence and acceptor absorption bands.     

Poly[2,4-bis(chloroamino)-6-vinyl-1,3,5-triazine] as a recyclable oxidizing agent of alcohols

A polymer containing dichlorotriazine moiety was prepared readily by the reaction of poly(2,4-diamino-6-vinyl-1,3,5-triazine) with tert-butyl hypochlorite. This polymer oxidizes various primary and secondary alcohols to the corresponding carbonyl compounds under mild conditions, while the reaction of the monomeric analogue N,N′-dichloroacetoguanamine with alcohols does not proceed. The polymer reagent can be handled easily and recycled for further use.