Utilization of ortho-alkynylarylcarbonyl derivatives for creating structurally diverse chemical compounds

Divergent synthesis of 3,4-dihydro-2H-benzo[h]chromen-2-one and fluorenone derivatives from ortho-alkynylarylketones

Our research has led to the development of a divergent synthesis approach for the synthesis of 3,4-dihydro-2H-benzo[h]chromen-2-one 3 and fluorenone 9 derivatives using ortho-alkynylarylketones as common precursors. The synthesis of 3,4-dihydro-2H-benzo[h]chromen-2-ones 3 employed silver catalyzed ketonization to form polycarbonyl intermediates which underwent double intramolecular cyclization and decarboxylation to generate a lactone and a phenyl ring in a one-pot fashion. In addition, the same precursor could be used to prepare fluorenone derivatives 9 under acidic conditions. The reaction proceeded via the formation of indenone analogs, followed by the generation of the para-quinone methide intermediate and intramolecular cyclization to provide the corresponding products in good yields.

Synthesis of Naphtho[2,3-d]oxazoles via Ag(I) Acid-Mediated Oxazole-Benzannulation of ortho-Alkynylamidoarylketones

A cascade oxazole-benzannulation for the synthesis of naphtho[2,3-d]oxazoles has been developed employing ortho-alkynylamidoarylketones as substrates. This procedure provides the advantage of preparing a wide variety of substituents on naphtho[2,3-d]oxazole structures. In addition, o-alkynylamidoarylketones could be prepared from easily accessible and a wide variety of commercially available starting materials. Therefore, this method is a judicious choice of strategy to synthesize naphtho[2,3-d]oxazoles with a great variety of substituents. In this work, 27 examples were demonstrated to provide the desired products in moderate to good yields.

Photoinduced C-C bond cleavage for the synthesis of 2,4-disubstituted-1-naphthols from indenone derivatives and sulfoxonium ylide

The synthesis of 2,4-disubstituted-1-naphthols has been developed employing photomediated C-C bond cleavage (UV-LED 390 nm) of cyclopropane fused-indanones generated in situ from the reaction between indenones and trimethylsulfoxonium chloride under basic conditions at room temperature. Seventeen substrates were examined in this study. The results showed that indenone precursors containing aryl substituents could smoothly provide the desired products in up to 81% yield.

Synthesis of dihydropyrroles from in situ-generated zwitterions via Rh2(adc)4/TBAI dual catalysis

A convenient rhodium/iodide dual catalysis strategy for the regioselective synthesis of dihydropyrroles was established.