Synthesis of N-substituted carbazolones from α-iodo enaminones via Pd(0)-catalyzed intramolecular coupling under microwave irradiation

Synthesis of 5-(2-hydroxyphenyl)-5-methyl-6H-benzo[c]carbazole-6-ones and their antitumor activities

A concise and efficient photo-induced rearrangement and oxidation of 2-(3-methylbenzofuran-2-yl)-3-phenyl-1H-indoles 1 for the synthesis of 5-(2-hydroxyphenyl)-5-methyl-5,7-dihydro-6H-benzocarbazol-6-ones 2 is described. Irradiation of compounds 1 in anhydrous dichloromethane solution, using 313 nm UV light in an air atmosphere, resulted in the formation of compounds 2 with yields ranging from 55% to 98%. Using the 6π-electrocyclization strategy of compounds 1 containing a methyl, a quaternary carbon stereocenter was introduced in the compounds 2. The carbonyl group of compounds 2 was formed by the photo-induced oxidation of C-H bond to C-OH and hemiketal-keto tautomerization. Additionally, the antitumor activities of compounds 2 were evaluated and found to demonstrate equivalent or superior activity compared to Cisplatin against various tumor cell lines, including leukemia HL-60, lung cancer A549, liver cancer HepG2, breast cancer MDA-MB-231 and colon cancer SW480. The anticancer activity of compound 2f was particularly significant, with IC50 values of 2.99, 9.06, 6.81, 9.29, and 14.93 μM respectively, and its IC50 value of normal cells 11.18 μM. Compound 2k had a relatively high IC50 values against cancer cells, whereas its IC50 value greater than 40μM for normal cells.

Photo-Fries-type rearrangement of cyclic enamides. An efficient route to structurally diverse five-membered enaminones

A simple, efficient and user-friendly protocol for the preparation of structurally diverse enaminones from enamides has been developed. The strategy is based on a photo-induced intramolecular Fries-type rearrangement. The photochemical transformation proceeds under mild reaction conditions, applies to a broad substrate range, is highly economic, and limits the amount of waste produced. The proposed methodology was used as a key step in the synthesis of dihydrojasmone an important fragrance compound.

Formation of 3-Aminophenols from Cyclohexane-1,3-diones

meta-Aminophenols are formed by the action of DBU on 3-amino-2-chlorocyclohex-2-en-1-ones at room temperature in MeCN. The chloro compounds are generated by treating 3-aminocyclohex-2-en-1-ones with the easily prepared halogenating agent BnNMe₃·ICl₂ in MeOH-CH₂Cl₂. The amino group must carry two substituents, either two aryl, one aryl and one alkyl, or two alkyl groups; 3-aminocyclohex-2-en-1-ones of this type are readily made from cyclohex-2-en-1-one and a primary or secondary amine.

MoO2Cl2(DMF)2 catalyzed microwave assisted reductive cyclisation of nitroaromatics into dibenzodiazepines

Microwave induced, MoO₂Cl₂(DMF)₂ catalyzed synthesis of novel dibenzodiazepine scaffolds with potential biocidal activity.

Efficient PPA-SiO2-catalyzed synthesis of β-enaminones under solvent-free conditions

An efficient method has been developed for the synthesis of β-enaminones under solvent-free reaction conditions using PPA-SiO₂ as catalyst. The reaction yields were good to excellent (up to 90%). This methodology affords high selectivity and good tolerance of a variety of different functional groups present on both aromatic and aliphatic amines. In addition, the methodology is environmentally benign and cost-effective due to absence of solvent and easy work-up.