Robert Bujok

General synthesis of 2,1-benzisoxazoles (anthranils) from nitroarenes and benzylic C–H acids in aprotic media promoted by combination of strong bases and silylating agents

Carbanions of phenylacetonitriles, benzyl sulfones, and dialkyl benzylphosphonates add nitroarenes at the ortho-position to the nitro group to form

Cocatalysis by tetravalent tin compounds in phase-transfer catalyzed fluorination of alkyl halides and sulfonates

\sigma ^\mathrm{H}

A general and convenient method for the synthesis of 2,4-dinitrobenzyl ketones. Almost unlimited access to 2-substituted 6-nitroindoles from 2,4-dinitrotoluene and aldehydes

σH-adducts that, upon treatment with trialkylchlorosilane and additional base (t-BuOK or DBU), transform into 3-aryl-2,1-benzisoxazoles in moderate-to-good yields.

Nitro-Substituted Hoveyda-Grubbs Ruthenium Carbenes: Enhancement of Catalyst Activity through Electronic Activation

Summary Alkylation of 5-nitroindol-4-ylacetonitriles with ethyl chloroacetate, α-halomethyl ketones, and chloroacetonitrile followed by a treatment of the products with chlorotrimethylsilane in the presence of DBU gives 1-cyanopyrrolo[3,2-e]indoles substituted in position 2 with electron-withdrawing groups.

Advanced fine-tuning of grubbs/hoveyda olefin metathesis catalysts: a further step toward an optimum balance between antinomic properties.

Abstract Phase-transfer catalyzed fluorination of alkyl halides or sulfonates is co-catalyzed efficiently by triorganotin halides. The cocatalytic action is due to continuous formation of lipophilic hypervalent triorganodifluorostannate anions, which act as fluorinating agents in the organic phase.

Structure and Activity Peculiarities of Ruthenium Quinoline and Quinoxaline Complexes: Novel Metathesis Catalysts

Anilines react with 5-nitroindoles in the presence of t-BuOK in N,N-dimethylformamide (DMF) to form 5-nitroso-4-arylaminoindoles that in turn when treated with N,O-bis(trimethylsilyl)acetamide cyclize to pyrrolo[3,2-a]phenazines. In an alternative approach pyrrolo[3,2-a]phenazines are formed from aminoindoles and nitroarenes.Graphical abstract

New tunable catalysts for olefin metathesis: Controlling the initiation through electronic factors

2,4-Dinitrotoluene reacts in the presence of catalytic amounts of DBU with aldehydes to form the corresponding alcohols in good yields (usually above 65%). The obtained alcohols can be readily oxidized to 2,4-dinitrobenzyl ketones, which were used for the synthesis of 6-nitroindoles with various substituents in the 2-position. Starting from non-racemic aldehydes, non-racemic 2-substituted 6-nitroindoles were obtained.