R. Kh. Freidlina

The rearrangement of polyhaloalkyl radicals in solution with 1,2-chlorine atom migration

Abstract Radicals XCCl 2 CYCH 2 Z (l; Xue5fbCl,H,F,CH 3 ; Yue5fbH,CH 3 ,Cl,Br; Zue5fbBr,Cl,CCl 3 ,SR) were generated by homolytic addition of addition of various addenda to unsaturated compounds XCCl 2 CYue5fbCH 2 . Radicals (I) were shown to rearrange in solution into radicals XCClue5f8CYClue5f8CH 2 Z (II), the latter being more stable than the former. It was found that compounds XCCl 2 CBrue5fbCH 2 with Xue5fbCl,CH 3 ,F could isomerize under the action of initiators of radical processes to compounds XCClue5fbCClCH 2 Br. This isomerization was proved to be of a radical chain character and involves the 1,2-chlorine migration in the intermediate radical XCCl 2 CBrCH 2 Br (III). The dependence between the structure of starting radicals and their ability to undergo rearrangement in solution has been established and the effect of the nature of addendum on the reaction course investigated. The polyhaloalkyl radicals were arranged in a sequence according to their relative stability.

The telomerization reaction and the chemical transformations of telomers

1. n nThe investigation revealed the great potentialities of telomerization in organic reactions. n n n n n2. n nTaking the telomerization of olefins with silanes as an example. the applicability of the telomerization reaction to the synthesis of heteroorganic compounds is demonstrated. n n n n n3. n nInvestigation of hetero- and homolytic reaction of α,α,α,ω-tetrachloroalkanes led to new routes for synthesis of diverse bi- and polyfunctional compounds. n n n n n4. n nHomolytic isomerization (not of the allylic type) was observed for the first time in the polyhalopropylene series.

Preparation of hexaalkoxydititanoxanes (RO)3Ti-O-Ti(OR)3

1. n nHexaethoxydititanoxane was prepared by the oxidation of triethoxytitanium. n n n n n2. n nHexapropoxy- and hexabutoxy-dititanoxides were prepared by the transesterification of hexapthoxydititanoxane.

Synthesis of unsymmetrical sulfides containing functional groups

1. n nIron pentacarbonyl and colloidal iron catalyze the addition of thiols to acrylic compounds with formation of products of structure RSCH2CH2R′, in which R=C4H9; C2H5OCO(CH2)4; R′=CN; CO2CH3. n n n n n2. n nDisulfides react with olefins at 170–200° in accordance with the scheme: n n

Synthesis and properties ofΒ-haloallyl compounds of mercury

RS - SR + CH_2 = CHR - left| {begin{array}{*{20}c} { to RSCH_2 CH_2 R,} { to RSCH_2 CH (R)SR,} end{array} } right.

Disproportionation reactions of organic compounds containing zirconium, titanium, and iron

n nin which R=C2H5; C2H5OCO(CH2)4; R′=H; C8H17. n n n n n3. n nThe telomerization of methyl acrylate with ethyl 5-mercaptovalerate was carried out in presence of benzoyl peroxide. The telomers C2H5OCO(CH2)4S(CH2CHCO2CH3)nH (n=1, 2, and 3), were isolated. Under the same conditions, reaction with acrylonitrile gave only addition products.

Addition of hydrogen bromide to 3,3-dichloropropene in presence of benzoyl peroxide

The reaction of telomerization of ethylene with carbon tetrachloride or chloroform is initiated by hexacarbonyls of chromium, molybdenum, and tungsten at 115–120‡, forming α,α,α,Ω-tetrachloroalkanes and α,α,α-trichloroalkanes. respectively.

New method for the preparation of alkoxy zirconium compounds

1. n nΒ-Haloallyl derivatives of mercury with the general structure CX2=CYCH2HgZ, where X=H or Cl, or Br, and Z is a halogen atom or anα-C10H7 radical were synthesized. n n n n n2. n nThe thermal stability of the compounds synthesized increased with the number of halogen atoms in the molecule.