210624-94-5Relevant academic research and scientific papers
Br?nsted acid-catalysed conjugate addition of photochemically generated α-amino radicals to alkenylpyridines
Hepburn, Hamish B.,Melchiorre, Paolo
, p. 3520 - 3523 (2016/03/04)
The conjugate addition of α-amino radicals to alkenylpyridines has been accomplished by the synergistic merger of Br?nsted acid and visible light photoredox catalysis. Key to reaction development was the protonation of the alkenylpyridines that transientl
Regiospecific [2 + 2] photocyclodimerization of trans-4-styrylpyridines templated by cucurbit[8]uril
Nakamura, Asao,Irie, Hiromi,Hara, Shuhei,Sugawara, Mai,Yamada, Shinji
scheme or table, p. 1496 - 1500 (2012/06/01)
Addition of HCl accelerated the photocyclodimerization of trans-4-styrylpyridine 1a in methanol and increased the yield of syn-head-to-tail (syn-HT) dimer 2a through the effect of cation-π interactions between the pyridinium ion of one molecule and the phenyl group of the other. We examined the photoirradiation products of derivatives of 1a having alkyl substituents on the phenyl group (1b-1f). The effect of the alkyl substituent on product distribution was rather limited for the photoreaction in MeOH solutions. However, the substituents had a distinct effect on the product distribution for the photoreaction of the inclusion complexes of hydrochloride salts of trans-4-styrylpyridines with cucurbit[8]uril in aqueous solutions. Introducing an alkyl group at the 2- or 3-position of the phenyl group completely shifted the major product from the syn-HT dimer to the syn-head-to-head (syn-HH) dimer. By adjusting the balance of host-guest interactions and cation-π interactions between guest molecules through systematic changes in the substituents on the phenyl ring of trans-4-styrylpyridine, we could change the orientation of the reactant molecules in the host cavity, resulting in a change of the major regioisomer of the photocyclodimerization products. The Royal Society of Chemistry and Owner Societies.
Electronic Interactions in Aromatic Compounds. Direct Electronic Interaction between Aromatic Rings in Conjugated and Non-Conjugated cis-Compounds
Mancini, Vittorio,Passini, Paolo,Santini, Sergio
, p. 463 - 466 (2007/10/02)
A study of charge transfer equilibria between a series of cis- and trans-4-styrylpyridines and cis- and trans-1-(4-X-phenyl)-2-(4-pyridyl)cyclopropanes with iodine has been carried out in CCl4.Acidity constants for these heteroaromatic compounds were determined.The results obtained for the two types of measurements show that through-space conjugation, due to overlap of the non-parallel ?-orbitals of the two aromatic systems, operated in both cis-systems.
