G. I. Nikishin

Convenient Synthesis of Geminal Bishydroperoxides by the Reaction of Ketones with Hydrogen Peroxide

Abstract A convenient procedure was developed for the synthesis of geminal bishydroperoxides by the sulfuric acid–catalyzed reaction of ketones with hydrogen peroxide in THF. Gem‐bishydroperoxides were prepared by the reactions of five‐ to seven‐membered cycloalkanones without additional purification in 80–95% yields with a purity of more than 95%; their acyclic analogs were prepared in 43–72% yields.

Electrochemical synthesis of cyclopropanes

Data on methods of electrochemical synthesis of cyclopropanes are summarized and described systematically. Direct electrochemical methods to afford cyclopropanes in both cathodic and anodic processes are considered. Among indirect electrochemical methods such as the processes employing electrogenerated bases and also those involving electrogenerated metal complexes, attention is focused on the most promising methods for the synthesis of functionally substituted cyclopropanes, namely, the electrocatalytic cascade and multicomponent transformations of CH acids and also the joint electrolysis of CH acids and activated alkenes or carbonyl compounds in the presence of alkali metal halides as mediators. The bibliography includes 62 references.

Electrocatalytic transformation of malononitrile and cycloalkylidenemalononitriles into spirotricyclic and spirotetracyclic compounds containing cyclopropane and pyrroline fragments

Electrolysis of cycloalkylidenemalononitriles and malononitrile in MeOH in an undivided cell in the presence of the NaBr—NaOMe mediator system gives spirotricyclic compounds containing cyclopropane and pyrroline fragments in 50—77% yields. Spirobicyclic and spirotricyclic tetracyanocyclopropanes undergo electrolysis in alcohols to afford spirotricyclic and spirotetracyclic products containing cyclopropane and pyrroline fragments in 50—93% yields.

Synthesis of peroxide compounds by the BF3-catalyzed reaction of acetals and enol ethers with H2O2

Aliphatic and alicyclic gem-bis-hydroperoxides and their derivatives, bis(1-hydroperoxycycloalkyl) and bis(1-hydroperoxyalkyl) peroxides, dispiro- and tetraalkyl-1,2,4,5-tetroxanes were synthesized by the reaction of aliphatic and alicyclic acetals and enol ethers with H2O2 in the presence of BF3 in anhydrous Et2O.

Electrocatalytic transformation of malononitrile and cycloalkylidenemalononitriles into spirobicyclic and spirotricyclic compounds containing 1,1,2,2-tetracyanocyclopropane fragment

Electrolysis of malononitrile and cycloalkylidenemalononitriles in EtOH in an undivided cell in the presence of NaBr affords spirobicyclic compounds containing a 1,1,2,2-tetracyanocyclopropane fragment in 50—88% yields.

Electrocatalytic transformation of dialkyl malonates and arylidene- or alkylidenemalononitriles into dialkyl esters of 3-substituted 2,2-dicyanocyclopropane-1,1-dicarboxylic acids

Electrolysis of alcoholic solutions of dialkyl malonates and arylidene- or alkylidenemalononitriles in the presence of NaBr in an undivided cell gave dialkyl esters of 3-substituted 2,2-dicyanocyclopropane-1,1-dicarboxylic acids in 60–90% yields.

Oxidation of 1-alkylcycloalkanols with PbIV and MnIII compounds under mechanical activation

A mechanoactivated solid-state oxidative decyclization of 1-alkylcycloalkanols under the action of the Pb(OAc)4−MX or Mn(OAc)3−MX systems (MX is a metal halide) was carried out for the first time. The reaction affords exclusively ω-haloalkanones.

ELECTROCHEMICAL TRANSFORMATION OF CYANOACETIC ESTER AND ALKYLIDENECYANOACETIC ESTERS INTO 3-SUBSTITUTED 1,2-DICYANOCYCLOPROPANE-1,2-DICARBOXYLATES

Electrolysis of cyanoacetic ester and alkylidenecyanoacetic esters in an undivided cell in the presence of mediators (alkali metal halides) gives rise to 3-substituted, 1,2-dicyanocyclopropane-1,2-dicarboxylates in 60–95% yields.

Stereoselective electrocatalytic transformations of malononitrile and aromatic aldehydes into (1R,5S,6R)*-4,4-dialkoxy-2-amino-6-aryl-1,5-dicyano-3-azabicyclo[3.1.0]hex-2-enes

Electrolysis of aromatic aldehydes and malononitrile in alcohols in an undivided cell in the presence of a NaBr-NaOAc mediatory system stereoselectively gave bicyclic compounds containing the cyclopropane and pyrroline fragments in 60 to 70% yields. In the bicyclic products, the benzene and pyrroline rings are on different sides of the cyclopropane ring.

Synthesis of nine-, ten-, and fifteen-membered alkenolides by the oxidative cleavage of the bridging C=C bond in 2-oxabicycloalkenes

Hydroperoxidation of C=C-bridged 2-oxabicycloalkenes in which the five- or six-membered oxacycle is fused with the five-, six-, or twelve-membered hydrocarbon ring was studied. The Cu(OAc)2-catalyzed decomposition of the resulting hydroperoxides afforded nine-, ten-, or fifteen-membered trans-alkenolides, respectively. The latter compounds were obtained as pairs of regioisomers, with the isomers in which the double bond is more remote from the ether oxygen atom predominating.