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Free Radical Addition and Cyclization Reactions of [2-(4-(S)-Isopropyl-2-oxazoline)-5-phenyl]dialkyltin Hydrides

Stępień A., Petrosyan A., Wilk M., Cmoch P., Rupnicki L., Staliński K.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 6

1015-1024

EN

Radical addition reactions of [2-(4-(S)-isopropyl-2-oxazoline)-5-phenyl]dibutyl and dimethyl hydrides to activated double/triple bonds took place in good yields. Triethylborane in presence of oxygen can serve as a radical initiator. Addition of stannyl radicals to N,N-(2-methoxycarbonyl-allyl)benzyl glycinate results in formation of the corresponding piperidine derivatives. The intramolecular tandem radical addition/ cyclization process can be performed in high yields and good diastereoselectivity.

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Application of Dialkyltin Hydrides Containing the Chiral 2-(4-Isopropyl-2-oxazolinyl)-5-phenyl Ligand in Radical Cyclizations at the Steady State

Pianowski Z., Staliński K.

Polish Journal of Chemistry

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2005

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Vol. 79 / nr 4

721-729

EN

New N-coordinated dimethyl and di-n-butyl tin hydrides containing the oxazole moiety appeared to be useful in radical cyclizations of acyclic dihalides at the steady state. Both the hydrides were prepared in three steps starting from (-)-(S)-(2-bromophenyl)- 4-isopropyl-4,5-dihydrooxazole. The advantages of the hydrides are at least twofold. First, a resolution of the radical intermediates allows generating higher stereomeric excess than in the case of commercially available hydrides. Second, tin by-products are easily removed.

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Stereoselection at the Steady State within radicals - How far can we go ?

Staliński K.

Polish Journal of Chemistry

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2004

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Vol. 78 / nr 5

611-622

EN

Stereoselection at the steady state is a process, which results from a complex interplay of reaction pathways that diverge and reconverge at various points. Therefore, it can be considered as a manipulation of stereocontrol mainly by reaction topography. The advantages of this process are at least twofold: First, stereoconvergence allows the system to exceed the yield of the initial stereoconvergent event, where stereomeric transition states compete. Second, a successive resolution of the reactive intermediates by chemoselective events allows the system to generate high stereomeric excess, practically without any stereoselective competition. While illustrated with radicals, the process may prove useful in other fields of chemistry.

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Oxidative Nucleophilic Substitution of Hydrogen in Nitroarenes : a Short Review

Mąkosza M., Staliński K.

Polish Journal of Chemistry

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1999

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vol. 73 nr 1

151-161

EN

Selected examples of oxidative nucleophilic aromatic substitution in nitroarenes are discussed with emphasis on the authors results. Generalization of this process is attempted.