Two cyclization modes are realized to produce different nitrogen-containing heterocycles, i.e., quinazolin-4(3H)-imines and acridines by assembling o-cyanoanilines and diaryliodonium salts via tandem reaction pathways.
Selective
C(sp3)–H isothiocyanation represents
a significant strategy for the synthesis of isothiocyanate derivatives.
We report herein an electrochemical benzylic isothiocyanation in a
highly chemo- and site-selective manner under external oxidant-free
conditions. The high chemoselectivity is attributed to the facile in situ isomerization of benzylic thiocyanates to isothiocyanates.
Notably, the method exhibits high functional group compatibility and
is suitable for late-stage functionalization of bioactive molecules.
A sequential one-pot two-step protocol for microwave-assisted synthesis of Hantzsch-type hexa-substituted 1,4-dihydropyridines has been developed. The three-component reactions of beta-aroylthioamides with aldehydes and acetonitrile derivatives produce the intermediates in situ followed by a S-alkylation to afford hexa-substituted 1,4-dihydropyridines. The reaction presumably proceeds via a Knoevenagel condensation-Michael addition-cyclocondensation-rearrangement-S N2 reaction sequence. Target compounds were obtained in high yields and simply purified by recrystallization. The novel method is complementary to the classical Hantzsch synthesis in that it is well-suited to the preparation of hexa-substituted 1,4-dihydropyridines.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.