As ynthetic protocol for the preparation of 5-(aryl)dibenzothiophenium salts starting from inexpensive dibenzothiophene S-oxide and simple arenes is reported. The scope of the method regarding the nature of the arene is evaluated, intermediates along the reaction sequence have been trapped, and side-reactions identified. In addition, the X-ray structures of acomplete set of these salts are reported and their reactivities studied. Specifically,c hemoselective Suzuki coupling is observed at the dibenzothiophenium in the presence of iodides.

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Synthesis, characterisation, and investigation of the luminescence features of a new class of chromophores: SBDIPY and BIDIPY.

A synthetic protocol for the preparation of 5‐(aryl)dibenzothiophenium salts starting from inexpensive dibenzothiophene S‐oxide and simple arenes is reported. The scope of the method regarding the nature of the arene is evaluated, intermediates along the reaction sequence have been trapped, and side‐reactions identified. In addition, the X‐ray structures of a complete set of these salts are reported and their reactivities studied. Specifically, chemoselective Suzuki coupling is observed at the dibenzothiophenium in the presence of iodides.

Zinc enolates derived from ethyl 4-bromo-2,2,4-trimethyl-3-oxopentanoate and 4-bromo-4-ethyl-2,2-dimethyl-3-oxohexanoate react with 2-furan-, 2-thiophene-, 1-(3-nitrophenyl)-2-pyrrole-, 1-acyl-3-indole-, and 2-pyridinecarbaldehydes to give the corresponding 6-hetaryl-5,5-dialkyl-3,3-dimethyltetrahydropyran-2,4-diones. Scheme 1. I, II, R = Me (a), Et (b); III, IV, R = Me, Het = 2-furyl (a), 2-thienyl (b), 1-(3-nitrophenyl)-2-pyrrolyl (d), 1-acetyl-3-indolyl (e), 1-propionyl-3-indolyl (g), 1-butyryl-3-indolyl (h); R = Et, Het = 2-thienyl (c), 1-acetyl-3-indolyl (f), 2-pyridyl (i).Compounds possessing a 2,4-dioxotetrahydropyran fragment are components of various natural products, and they exhibit versatile biological activity [1-3]. We previously developed a new approach to the synthesis of 6-alkyl-, 6-alkenyl-, and 6-aryl-substituted tetrahydropyran-2,4-diones via Reformatsky reaction [4]. The goal of the present work was to elucidate the possibility for synthesizing analogous compounds having hetaryl groups in position 6 of the pyran ring. For this purpose, ethyl 4-bromo-2,2,4-trimethyl-3-oxopentanoate (Ia) and ethyl 4-bromo-4-ethyl-2,2-dimethyl-3-oxohexanoate (Ib) were converted by treatment with metallic zinc into the corresponding zinc enolates IIa and IIb which were brought into reaction with 2-furan-, 2-thiophene-, 1-(3-nitrophenyl)-2-pyrrole-, 1-acyl-3-indole-, and 2-pyridinecarbaldehydes. Primary intermediate adducts IIIa-IIIi underwent spontaneous intramolecular cyclization to afford 6-hetaryl-5,5-dialkyl-3,3-dimethyl-2,3,5,6-tetrahydropyran-2,4-diones

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Zinc enolates formed from 1-aryl-2-bromo-2-phenylethanones and zinc react with dimethyl 2-(1-arylmethylene)malonates to afford dimethyl 2-(1,3-diaryl-3-oxo-2-phenylpropyl)malonates. The latter react with cyclohexylamine, piperidine, or morpholine to give the corresponding monosubstituted amides. The zinc enolate derived from 2-bromoindanone and zinc reacts with dimethyl 2-(4-bromobenzylidene)malonate, yielding dimethyl 2-[(4-bromophenyl)(1-oxoindan-2-yl)methyl]malonate. The final products largely form as a single diastereomer.Condensations of dialkyl a-benzylidenemalonic acid esters with carbonyl compounds under the action of bases have been exemplified in the literature [1]. However, the reported condensation procedures feature a number of drawbacks, such as long reaction time (>20 h), low product yields (<25 %), and formation of a mixture of mono-and dialkyl esters of malonic acid. ÄÄÄÄÄÄÄÄÄÄÄÄIn the present communication we report the results of research on the reaction of zinc enolates IIa3IId generated from a-bromoketones Ia3Id and zinc under Reformatskii reaction conditions, with dimethyl 2-(1-arylmethylene)malonates IIIa and IIIb. The reaction probably occurs by the following scheme.

2005 Pyran derivatives R 0340Synthesis of 6-Hetaryl-5,5-dialkyl-3,3-dimethyltetrahydropyran-2,4-diones by Reformatsky Reaction. -The interesting title compounds such as (III) are prepared in an one-pot procedure. -(SHCHEPIN, V. V.; KORZUN, A. E.; SAZHNEVA, Y. K.; Russ.