ORIGINAL PAPER Kinetic study of dichlorocarbene addition to olefins via a quaternized highly branched polyacrylamide as a new multi-site phase transfer catalyst Hossein Mahdavi • Mehdi Amirsadeghi Received: 5 February 2012 / Accepted: 25 June 2012 / Published online: 20 July 2012 Ó Iran Polymer and Petrochemical Institute 2012 Abstract A quaternized highly branched polyacrylamide was synthesized and used as an efficient multi-site poly- meric phase transfer catalyst in dichlorocyclopropanation reaction. The quaternized highly branched polyacrylamide was synthesized via two steps. First, a highly branched polyacrylamide was synthesized via self-condensing vinyl polymerization using appropriate molar ratio of monomer to diperiodatocuprate(III) solution. In the second step, 3-acrylamidopropyltrimethylammonium iodide was poly- merized on peripheral area of the highly branched poly- acrylamide in the presence of diperiodatocuprate(III) solution. The thermal behavior of highly branched poly- acrylamide and that of the quaternized highly branched polyacrylamide was studied by DSC and TGA analyses. Then the activity of the synthesized quaternized highly branched polyacrylamide was investigated as phase trans- fer catalyst in dichlorocyclopropanation of olefins in biphasic medium. To this purpose, the synthesized catalyst was used in generating dichlorocarbene from chloroform in aqueous sodium hydroxide solution which was subse- quently added to olefins. This catalyst is very active and its application yields high volume of products which are obtained in relatively short time. Various factors which influence the rate of dichlorocyclopropanation reaction, such as base concentration, stirring speed, temperature and amount of catalyst, are studied and a mechanism for addition reaction of dichlorocarbene to olefins is proposed. This efficient phase transfer catalyst was reused several times without any loss of activity. Keywords Highly branched polyacrylamide Á Self-condensing vinyl polymerization Á Multi-site phase transfer catalyst Á Dichlorocyclopropanation Introduction Many kinds of phase transfer catalysts (PTC) have been synthesized and used to carry out biphasic reactions. Most of these catalysts have a structure of onium salts (quater- nary ammonium and phosphonium salts), crown ethers, cryptands and polyethers (polyethylene oxide) in common, among which onium salts have more applications due to their good activity and economic viewpoint especially in industrial application [1, 2]. Most of the synthesized PTCs have single-site structure but recently more attention has been paid to synthesis multi-site PTC [3, 4]. The multi-site PTC has a potential for providing greater activity and also accelerating partic- ular synthetic transformation even under mild conditions. The first published report on multi-site PTC was by Idoux et al. [5]. They have synthesized both soluble and insoluble quaternary phosphonium salts containing three active sites per each molecule. Balakrishnan et al. [6, 7], and Wang et al. [8] have also reported soluble ammonium quaternary onium ions having two active sites. They examined the efficiency of the two-site PTC through simple S N 1 reactions and some weak nucleophilic S N Ar reactions. gem-Dihalocyclopropanes play important role in organic synthesis [9]. They are valuable substrates for the preparation of monohalocyclopropanes, cyclopropanes, cyclopropenes, benzocyclopropenes, bicyclobutanes, allenes, cyclopentane and many other hydrocarbon systems [10, 11]. Elimination of hydrogen halide molecule from a haloform is known as the most important and frequently used method H. Mahdavi (&) Á M. Amirsadeghi School of Chemistry, College of Science, University of Tehran, PO Box 14155-6455 Tehran, Iran e-mail: hmahdavi@khayam.ut.ac.ir Iran Polymer and Petrochemical Institute 123 Iran Polym J (2012) 21:641–649 DOI 10.1007/s13726-012-0070-x