Mátyás Milen

Solid–Liquid Phase Alkylation of N-Heterocycles: Microwave-Assisted Synthesis as an Environmentally Friendly Alternative

The solid–liquid phase alkylation of a variety of five-membered N-heterocycles (carbazole, imidazole, benzimidazole, and indole-3-carbaldehyde) was carried out under different conditions. The use of alkali carbonate in dimethylformamide or in MeCN (in the latter case, in the presence of a phase-transfer catalyst) is a suitable method to prepare the corresponding N-alkylated products in an efficient way. In most cases, the solventless, microwave-assisted reaction is an environmentally friendly alternative to traditional methods.

Synthesis of α-Aminophosphonate Derivatives by Microwave-Assisted Kabachnik–Fields Reaction

GRAPHICAL ABSTRACT Abstract The synthesis of aminophosphonates was studied in aqueous solution using triethyl phosphite and under solvent-free and microwave-assisted conditions using >P(O)H species and starting from primary amines or α-, β- and γ-amino acid derivatives. The synthesis of bisaminophosphonates from suitable bifunctional compounds was also investigated in the presence of the T3P reagent.

Microwave-assisted synthesis of thioamides with elemental sulfur

Thioamides are valuable intermediates in organic chemistry (1). Moreover, this functional group constitutes an important part of some pharmacophores with widespread applications (2).A number of methods have been reported in the literature for the preparation of thioamides. In general, they were synthesized from the corresponding nitriles using thioacetic acid (3), O,O-dialkyl dithiophosphates (4), diphenylphosphinodithioic acid (5), sodium trimethylsilanethiolate (6), Dowex SH (7), or sodium hydrogen sulfide/diethylamine hydrochloride (8) as the reagent. Thioamides have also been prepared from amides, reacting them with tetraphosphorus decasulfide, either with or without additives (9), or using Lawesson’s reagent (10), ethylaluminum sulfide (11), or boron sulfide (12). Another method for the synthesis of thioamides utilizes elemental sulfur in the Willgerodt–Kindler reaction involving amines and aldehydes or ketones (13). Sulfur as a simple, inexpensive, and versatile reagent has been used in numerous organic transformations in the past several years (14). Our aim was to study the reaction of a variety of arylmethylamine derivatives with elemental sulfur under microwave (MW) conditions.

A Study on the Phosphorylation of Indole, Imidazole, Carbazole, and Phenothiazine Derivatives

Abstract N-Heterocycles including indolecarbaldehyde, substituted benzimidazoles, and methylimidazole could be efficiently phosphorylated by diethyl chlorophosphate at room temperature in different solvents using alkali carbonate or triethylamine as the base. However, the phosphorylation of N-heterocycles with a lower reactivity at the NH function, such as carbazole and phenothiazine, could not be conducted to complete conversion under the conditions applied.

Microwave-Assisted Esterification of Phosphinic Acids by Alcohols, Phenols, and Alkyl Halogenides

Abstract Cyclic phosphinic acids undergo direct esterification with alcohols at ca. 200°C under microwave conditions.

CCDC 1520212: Experimental Crystal Structure Determination

Related Article: Tamas Foldesi, Andras Dancso, Gyula Simig, Balazs Volk, Matyas Milen|2017|Mol.Diversity|21|903|doi:10.1007/s11030-017-9765-4

Total synthesis of racemic 1-aryl-tetrahydroisoquinoline alkaloids

A new synthetic route was developed for the preparation of natural products cryptostyline I, II, III and 1-phenyl-6,7-dimethoxy-2-methyl-1,2,3,4-tetrahydroisoquinoline. The Liebeskind–Srogl palladium-catalyzed carbon–carbon cross-coupling protocol was used in the key step of the total synthesis.Graphical abstract