Construction of Polyaromatic Hydrocarbons Containing Sulfur and Nitrogen via Controllable Domino Reactions and DFT Studies

Abstract

Polyaromatic hydrocarbons (PHAs) containing heteroatoms have attracted considerable attention due to their potential utility in electronic devices. This work reported a novel domino reaction between an aryne precursor and azadiene bearing a benzothiophene moiety to produce a series of PHAs containing sulfur and nitrogen atoms. Further transformation of the product enabled concise synthesis of a new AIEgen, whose photophysical properties were characterized. Density functional calculations on the reaction mechanism revealed that the in situ generated aryne could trigger either a [4 + 2] or [3 + 2] process with azadiene, in which the regioselectivity was mainly a result of the heteroatom effect and may be understood by means of Houk's distortioninteraction model.

Base-promoted selective C2–N1 ring-expansion reaction of indolones toward substituted quinolines

“…For example, in the presence of MeOTf, the tert-butylcarbonyl group of 3a could be selectively hydrolyzed to afford formic acid 4a in 93% yield. 12 However, the ethoxycarbonyl group was hydrolyzed to formic acid derivative 5a with KOH in 91% yield. 13 In order to clarify the reaction mechanism, several mechanistic experiments were performed (Scheme 3).…”

Streamlined Synthesis of Varied Heteroarene-Condensed Benzofuran Derivatives via [4 + 2] Annulation of Benzofuran-Derived Azadienes and N-Alkyl Quinolinium Salts

“…Drawing on existing literature, ,, we proposed a plausible mechanism for the cycloaddition reaction, which is hypothesized to occur under rhodium catalysis, as illustrated in Scheme . Initially, the in situ formed effective rhodium hydride reducing agent is expected to expedite the reduction of the N -alkyl quinolinium salt 2a , generating the active enamine intermediate A .…”