The Infra-red Spectra of Complex Molecules.

A new method is presented for 1,3-difluorination and 1,3-oxyfluorination reactions. The process is based on iodonium mediated opening of 1,1-disubstituted cyclopropanes. The reaction proceeds with high chemo- and regioselectivity under mild reaction conditions typically at room temperature in a couple of hours. The reaction probably occurs via electrophilic ring-opening of cyclopropanes.

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Fluorinative ring-opening of cyclopropanes by hypervalent iodine reagents. An efficient method for 1,3-oxyfluorination and 1,3-difluorination

Lewis Basic Sulfide Catalyzed Electrophilic Bromocyclization of Cyclopropylmethyl Amide

A facile and effective system has been developed for the regio- and chemoselective ring-opening/electrophilic functionalization of cyclopropanes through C-C bond activation by [bis(trifluoroacetoxy)iodo]benzene with the aid of the Lewis basic promoter p-toluenesulfonamide. The p-toluenesulfonamide-promoted system works well for a wide range of cyclopropanes, resulting in the formation of 1,3-diol products in good yields and regioselectivity.

Lewis Base-Promoted Ring-Opening 1,3-Dioxygenation of Unactivated Cyclopropanes Using a Hypervalent Iodine Reagent

Homohalocyclization: Electrophilic Bromine-Induced Cyclizations of Cyclopropanes.

Reactions of potassium dihaloiodates with arylcyclopropanes and polycyclic compounds containing a cyclopropane fragment characterized by different degrees of strain lead to formation of mixed 1,3-halogenation products. If iodohalogenation should give rise to products having a iodine atom in the benzylic position, 1,3-dichloro or 1,3-dibromo derivatives are formed. Iodohalogenation of exo-tricyclo[3.2.1.02,4]octane is stereoselective and is accompanied by Wagner-Meerwein rearrangement.

Reactions of cyclopropanes with potassium dihaloiodates

Studies of nitrosation of norbornene and norbornadiene derivatives and dimethyl tricyclo[4.2.2.02,5]deca-3,7-diene-9,10-cis-endo-dicarboxylate demonstrated that nitrosation of alkenes with EtONO-PHal3, EtONO-POHal3 (Hal = Cl or Br), and EtONO-SOCl2 systems can afford nitroso halides in high yields without the formation of by-products (ketones and oximes). The reactions with 5-substituted norbornenes are nonregioselective. The trans dimer of endo-5-trifluoromethyl-cis-exo-2-chloro-3-nitrosobicyclo[2.2.1]heptane was studied by X-ray diffraction.

New systems for classical nitrosohalogenation of alkenes 1. Reactions of alkenes with ethyl nitrite in the presence of phosphorus halides and thionyl chloride

Study of the reactions of compounds of the norbornene series demonstrated that the AgNO2-SOCl2 and AgNO3-SOCl2 systems serve as nitrosochlorinating agents under the conditions of electrophilic addition. X-ray diffraction study showed that dimerization of cis-exo-2-chloro-3-nitrosobicyclo[2.2.1]heptane occurs heterostereospecifically. The origin of the active principle of the reagents is discussed.

New systems for classical nitrosohalogenation of alkenes 2. Generation of nitrosyl chloride in AgNO2-SOCl2 and AgNO3-SOCl2 systems

The reactions of diaryl-, aryl-, and alkyl–arylcyclopropanes with ethyl nitrite in the presence of sulfur trioxide and sulfur trioxide dioxane complex, as well as the reactions of 1-alkyl-2-arylcyclopropanes with NOBF4 were studied It was found that the attack of the nitrosonium cation, accompanied by the formation of a benzyl carbocation, leads to the formation of isoxazolines The introduction of bulky alkyl substituents into the cyclopropane ring changes the regioselectivity of nitrosation, favoring the attack of the electrophilic particle on the benzyl position and leading to the competitive formation of an alkyl carbocation Depending on the structure of the alkyl substituent, both products of intramolecular heterocyclization accompanied by skeletal rearrangements and products formed with the participation of an external nucleophile are formed

V. N. Tikhanushkina

Papers

Reactions of cyclopropanes with potassium dihaloiodates

New systems for classical nitrosohalogenation of alkenes 1. Reactions of alkenes with ethyl nitrite in the presence of phosphorus halides and thionyl chloride

New systems for classical nitrosohalogenation of alkenes 2. Generation of nitrosyl chloride in AgNO2-SOCl2 and AgNO3-SOCl2 systems

Study of the Features of the Reaction of Arylcyclopropanes with Nitrozonium Ethyl Sulfate or Nitrozonium Tetrafluoroborate

4,5‐Dihydroisoxazoles from Arylcyclopropanes. Part 2. Reaction of Arylcyclopropanes with Nitrosyl Chloride Activated by Sulfur(VI) Oxide.