A. A. Tomashevskii

New one-step procedure for the synthesis of 6H-chromeno[4,3-b]quinolines and 8a,9,14,14a-tetrahydro-8H-benzo[5,6]chromeno[4,3-b]quinolines

Schiff bases generated in situ from substituted anilines and 2-allyloxybenzaldehyde underwent acid-catalyzed intramolecular Diels-Alder reaction followed by dehydrogenation to give 6H-chromeno[4,3-b]-quinolines. Under analogous conditions, derivatives of 2-allyloxynaphthalene-1-carbaldehyde were converted into 8a,9,14,14a-tetrahydro-8H-benzo[5,6]chromeno[4,3-b]quinolines. Possible dehydrogenation mechanisms are discussed.

Methods of Sultam Synthesis

Methods for preparing mono- and polycyclic sultams are systematically reviewed.

Addition of organometallic reagents to nitriles promoted by titanium(IV) isopropoxide as a procedure of synthesis of primary tert-alkylamines

Grignard reagents are able to add twice to nitriles in the presence of titanium(IV) isopropoxide providing primary tert-alkylamines in a fair yield. The conditions and structural features of reagents required for successful reaction were established. A possibility to apply two different organometallic reagents was demonstrated, in particular, the use of organolithium compounds in the second stage.

Reactions of 2-(α-Haloalkyl)thiiranes with Nucleophilic Reagents: IV. Alkylation of Sulfonamides with 2-Chloromethylthiirane. Synthesis and Properties of 3-(Arylamino)thietanes

Alkylation of primary and secondary sulfonamides with 2-chloromethylthiirane in the presence of alkali gives the corresponding N-(thiiran-2-ylmethyl)- and/or N-(thietan-3-yl)sulfonamides. The selectivity of the process depends on the solvent: in water, thiirane-thietane rearrangement products are formed exclusively, while ethanol favors Ad-E reaction leading to thiiranylmethyl derivatives. A procedure has been proposed for the synthesis of 3-(arylamino)thietanes which undergo selective acylation at the nitrogen atom. The possibility for synthesizing analogous derivatives of thietane 1-oxide and thietane 1,1-dioxide is considered.

Reaction of 4-(N,N-Dimethylaminophenyl)magnesium Bromide with Palladium Tetrakis(triphenylphosphine)

Abstract(α-Chloroalkyl)thiiranes react with sodium phenolates at heating in water-alcohol mixtures furnishing phenoxymethylthiiranes, 3-phenoxythietanes (resulting from thiirane-thietane rearrangement), or their mixture. The increased polarity of solvent favors the thiirane-thietane rearrangement. 2,2-Dimethyl-3-(chloromethyl)thiirane forms an exclusion for it does not afford (phenoxymethyl)thiirane even in anhydrous ethanol. Diastereomeric erythro- and threo-(1-chloroethyl)thiiranes react stereospecifically giving 2-methyl-3-phenoxymethylthiiranes or 2-methyl-3-phenoxythietanes of trans- and cis-configuration respectively. Specific features of these reactions are discussed from the viewpoint of solvent polarity effect on the competition between formal chlorine substitution along “recyclization” mechanism or through thiirane-thietane rearrangement.

Alkylation of N-arylcyanamides and electron-deficient phenols with (chloromethyl)thiirane

Alkylation of N-arylcyanamides with (chloromethyl)thiirane in aqueous alkaline solution provides an easy synthetic approach to N-aryl-N-(thietan-3-yl)cyanamides. Yields vary from 34 to 76% and are lower in the case of electron-deficient aryl substituents. The reaction with phenols containing electron-withdrawing groups results in formation of 3-(aryloxy)thietanes in 19–45% yields.

Reactions of 2-(α-Haloalkyl)thiiranes with nucleophilic reagents: V. Reactions of 2-(α-Chloroalkyl)thiiranes with organolithium compounds

Abstract2-(α-Haloalkyl)thiiranes reacted with methyl-, butyl-, and phenyllithium to give the corresponding allyl sulfides. The reactions of diastereoisomeric erythro- and threo-2-(1-chloroethyl)thiiranes with phenyllithium were stereospecific, and they afforded (E)- and (Z)-1-phenylsulfanylbut-2-enes, respectively. 3-Chloromethyl-2,2-dimethylthiirane and phenyllithium gave rise to a mixture of 3-methyl-3-phenylsulfanylbut-1-ene and 3-methyl-1-phenylsulfanylbut-2-ene. The reactions of 2-chloromethylthiiranes with phenyllithium and methyllithium in the presence of a catalytic amount of copper(I) iodide (10 mol %) led to the formation of substituted thiiranes as the major products. Mechanisms of the observed transformations are discussed.