Synthesis and Properties of Cleavable Quaternary Ammonium Compounds.

Quaternary ammonium compounds are widely used as antiseptic and disinfectant. It is been a concern that their widespread use will lead to an increase of environmental problems, therefore the development of biodegradable surfactants is necessary. The present research is aimed at the design of novel amphiphilic molecules with similar properties to those already known but more biodegradable.

Room-temperature and transition-metal-free Mizoroki-Heck-type reaction. Synthesis of E-stilbenes by photoinduced C-H functionalization.

We report a conceptually different approach toward E-stilbene syntheses by photoinduced direct C-H arylation of alkenes at rt without the addition of transition metals, with a broad range of aryl halides, including ArI, ArBr, and even ArCl. This is the first time that this reaction has been produced without extra solvent but with 18-crown-6 ether and t-BuOK in only 15 min of reaction.

Room-temperature photoinduced direct C-H-arylation via base-promoted homolytic aromatic substitution.

Conceptually different approach toward biaryl syntheses by photoinduced direct C-H arylation of benzene and thiophene in the presence of t-BuOK is reported. The reaction proceeds through photo- and base-promoted homolytic aromatic substitution. The o-, m- and p- substituted ArI, as well as the electron-donating and electron-withdrawing nature of the substituents were found be good to excellent substrates.

Synthesis of 6-substituted 2-pyrrolyl and indolyl benzoxazoles by intramolecular O-arylation in photostimulated reactions.

The synthesis of a series of 6-substituted 2-pyrrolyl and 2-indolyl benzoxazoles by photostimulated C-O cyclization of anions from 2-pyrrole carboxamides, 2-indole carboxamides, or 3-indole carboxamides has been found to proceed in good to excellent yields (41-100%) in DMSO and liquid ammonia. The pyrrole and indole carboxamides are obtained in good to very good isolated yields by an amidation reaction of different 2-haloanilines with 2-carboxylic acid of pyrrole and 2- or 3-carboxylic acid of indole. To explain the regiochemical outcome of these reactions (C-O arylation vs C-N or C-C arylation), a theoretical analysis was performed using DFT methods and the B3LYP functional.

Synthesis of benzo-fused heterocycles by intramolecular α-arylation of ketone enolate anions.

A two-step synthesis of six-, seven-, eight-, and nine-member benzo-fused heterocycles in good to excellent yields is reported. The synthetic strategy involves the generation of a new intramolecular α-aryl ketone bond by the photostimulated S(RN)1 reaction of ketone enolate anions linked to a pendant haloarene as the key step. On the other hand, an intramolecular C(Ar)-C(Ar) coupling led to the formation of five- and six-member benzo-fused heterocycles (9H-carbazole and phenanthridine) when an aromatic amide anion is competitively formed.