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Complex Catalysts for Polymer Chemistry

#A-447


Complex Catalysts in the Stereocontrolled Intramolecular Cyclization Reaction of Unsaturated Polyhalogencarbonyl Compounds into Carbocycles

Tech Area / Field

  • CHE-SYN/Basic and Synthetic Chemistry/Chemistry

Status
3 Approved without Funding

Registration date
28.12.1999

Leading Institute
Scientific Technological Center of Organic and Pharmaceutical Chemistry / Institute of Organic Chemistry, Armenia, Yerevan

Supporting institutes

  • NPO Nairit, Armenia, Yerevan

Project summary

COMPLEX CATALYSTS IN THE STEREOCONTROLLED intramolecular CYCLIZATION OF POLYHALOGENALKENOIC ACIDS

Achievements in the field of telomerization of monomers with halogenorganic derivatives in the last decade were connected mainly with application of transition metal based catalysts and the systems on their basis as initiators. From theoretical point of view investigation of reactions of stereoselective intramolecular cyclization of the derivatives of unsaturated poly-halogenecarbonyl compounds into the functionally substituted carbocyclic systems particularly with small and medium size cycles is a very important and challenging task. These compounds are widely used in organic synthesis for preparation of various medicines, environmentally safe methods of plant protection, as well as natural bioregulators, etc.


R=nitrile, COR1, R1=alkyl, O- alkyl, N- alkyl,hydroxyl, halogen; Y= chlorine, bromine;


Z=H, alkyl, phenyl, chlorine, bromine; X= halogen; n=1,2,3,4.


Starting a-halogencarbonyl compounds and their derivatives can be obtained by liquid phase oxidation of vinylhalogens by air, which is the most simple and readily available method for synthesis of substituted halogenoxiranes and acyl halides:


X= chlorine, bromine; Y= H, alkyl, chlorine, bromine; R= alkyl, cycloalkyl, halogen,


phenyl, hydroxy, alkoxy, acyloxy, alkenyl etc.


It should be noticed that in recent years many halogenvinyl compounds have already become available and cheap raw materials due to introduction of new and effective methods of chlorination of alkenes, alkynes, alkadienes, and other petrochemicals. Thus the problem of development of new effective methods of their selective oxidation is becoming more actual. The main objectives of the Project are:

— Development of simple and useful method of non-catalytic liquid phase oxidation of readily available mono-, di- and poly-halogenvinylic compounds by air:


- synthesis of chemicals important for practical purposes: halogenanhydrides of a-halogen organic acids;
- determination of optimal conditions for carrying out targeted oxidation of halogenvinylic compounds;
- studies of kinetic regularities of oxidation reaction, and regulation of reactivity of the halogenvinylic compounds depending on their structure.

— Development of methods of synthesis of substituted carbocyclic compounds by intramolecular cyclization reaction of the derivatives of unsaturated a-halogencarbonyl compounds in the presence of transition metal based catalysts:


- studies of intramolecular cyclization regularities;
- studies of the cyclization mechanism, finding out optimal conditions of the reaction: (catalyst and substance) for targeted stereocontrolled synthesis of substituted cyclic systems with certain location of substitutes in the ring.

Participants of the Project: - Institute of Organic Chemistry of National Academy of Sciences of the Republic of Armenia (IOC NAS RA) and“Nairit” Scientific–Industrial Closed Joint Stock Company (“Nairit” SI JSC). These institutions are the leading centers in this field not only in Armenia but also on the territory of the former USSR.

Prof. Shaliko Badanian is the Project Manager, he is an active member of the Armenian NAS, besides 3 Drs. of Sci. and 13 Ph.Ds. take part in the Project. In the Institute of Organic Chemistry NAS RA for many years works have been carried out in the field of studies of the reactions of unsaturated compounds, such as alkenes, alkadienes, alkynes, alkadiines and etc. by using them in synthesis of environmentally safe natural bioregulators. In the “Nairit” SI JSC for many years works have been carried out in the field of synthesis of different halogenvinyl compounds and their properties study, as well as development of optimal and environmentally safe utilization methods of industrial halogenorganic wastes. It is supposed that study of the substituted halogenvinyl compounds oxidation by air must lead to the development synthesis methods of series of important chemicals, as well as to solution of certain environmental problems related to utilization of halogenorganic industrial wastes. The new fields of application of the reaction (developed in IOC NAS RA) of intramolecular stereocontrolled cyclization reaction of the polyhalogenhexenic acids derivatives into unique cyclobutane derivatives will be found. The carbocyclic compounds, which are planned to synthesize could be convenient synthons in syntheses of physiologically active substances.

Synthesis of unsaturated a-halogencarbonyl compounds will be carried out using the reaction of non-catalytic liquid phase oxidation of halogenvinyl compounds or addition reaction of halogenorganic acids to various unsaturated compounds. One of the most important tasks of the Project will be finding out regularities and conditions of stereocontrolled intramolecular cyclization of polyhalogenalkenic compounds into functionally substituted cyclic structures in the presence of transition metal based catalysts. The Project supposes to carry out studies for solving the problems related to utilization of chloroorganic wastes of “Nairit” SI JSC On the basis of functionally substituted carbocyclic molecules with fixed space location of substitutes in the ring syntheses of physiologically active substances will be carried out. In order to study kinetic regularities and mechanism of the reaction we plan to use various initiators, catalysts, inhibitors as well as spin trapping method. Kinetics studies of liquid phase oxidation reaction of halogenolefines are based on measurements of oxygen absorption rate (manometric method) and speed of consumption of halogenvinyl compounds, and formation of the finished products by GLC method. On the basis of the kinetic studies we plan to develop a pilot device and to optimize parameters of the reaction of non-catalytic liquid phase oxidation reaction.

It is planned to carry out cyclization reaction of unsaturated a-halogencarbonyl compounds in the presence of different transition metal based catalysts changing solvents, co-initiators and catalysts. Stereochemical regularities of cyclization reaction will be studied using complexes of different stereochemical structure and nucleophilic-electrophilic properties of ligands and substitutes in the starting halogencarbonyl compounds.

The following methods of analytical and quality control methods of the reactions and products will be used: GLC, HPLC. For determination of intermediate compounds character ESR as well as preparative chromatography methods will be used. For determination of the finished products structure it is supposed to use different spectroscopy methods: NMR (300 Mhz), IR, UV and mass-spectroscopy methods, preparative chromatography and other physico-chemical methods of analysis.

It is supposed that foreign collaborators will participate in information exchanges, in discussions of the results obtained during implementation of the Project, as well as in evaluation of the progress reports, taking part in joint workseminars.

The accomplishment of the Project tasks will allow to solve a number of problems that meet goals of the ISTC:

· Reorientation of the scientists, engineers and engineering workers prior engaged in creation of weapons of mass destruction in developing new civilian technologies;

· Promotion in integration of the scientists from the CIS into international scientific community;

· Support for fundamental research and development for peaceful means;

· Provision of a long-term perspective for professional activities in civilian fields and preventing migration of specialists prior engaged in military sphere in Armenia to the neighbouring countries;

· Promotion of development of market economy in Armenia, etc.


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