RESUMEN
We have developed a series of 2-monoaryl-5-diarylmethylene analogs of the green fluorescent protein chromophore to study their viscosity-induced emission (VIE) properties. The analogs were synthesized by a condensation with methyl imidate and N-(diarylmethylene)glycinate. Among the analogs, the N-methylpyrrol-2-yl-substituted analog 1h induced the most remarkable VIE behavior in triglyceride and lipid bilayers probably due to the high π-electron-rich property of the pyrrole ring. The pyrrole substituent in imidazolone analogs can be expected to become a common template for introducing VIE behavior.
Asunto(s)
Imidazoles , Pirroles , Pirroles/química , Pirroles/síntesis química , Viscosidad , Imidazoles/química , Imidazoles/síntesis química , Estructura Molecular , Membrana Dobles de Lípidos/química , Proteínas Fluorescentes Verdes/químicaRESUMEN
Migratory cycloisomerization using transition metal catalyst is useful for synthesizing substituted heterocyclic compounds. We achieved palladium-catalyzed migratory cycloisomerization of 3-o-alkynylphenoxy acrylic acid ester derivatives to give 2,3-disubstituted benzofurans. Although there are several reports of benzofuran synthesis with palladium-catalyzed migratory cycloisomerization, migratory groups are limited to allyl and propargyl groups. This report is the first example of benzofuran synthesis with palladium-catalyzed cycloisomerization of C(sp2)-O bond cleavage.
Asunto(s)
Benzofuranos , Compuestos Heterocíclicos , Paladio/química , Benzofuranos/química , CatálisisRESUMEN
Herein, we report a ring-opening 1,3-arylboration of aryl cyclopropanes using BCl3 in the presence of arene nucleophiles. Formal 1,3-oxy arylation and 1,3-amino arylation of the arylcyclopropane via one-pot derivatization of the installed boron group were also achieved.
RESUMEN
Acetals are the most useful protecting groups for carbonyl functional groups. In addition to the role of protection, they can also be used as synthons of carbonyl functions. Previously, we developed a chemoselective deprotection and nucleophilic substitution of acetals from aldehydes in the presence of ketals. This article describes the highly discriminative and chemoselective transformations of acetals bearing different substitution patterns, different types of acetals, as well as mixed acetals. These reactions can achieve the transformations that cannot be attained by conventional methods, and their results strongly suggest the combination of R3SiOTf/2,4,6-collidine to promote such unprecedented phenomena.
RESUMEN
The intermediates formed during the Beckmann fragmentation of α-alkoxy and α-alkoxy-α-alkyl oxime acetates have been successfully trapped as phosphonium salts, which were subsequently reacted with a variety of Grignard reagents to give the corresponding substituted products in good yields. Notably, this reaction proceeded smoothly even from α-alkoxy-α-alkyl oxime acetates.