Synthesis Of Thiazolidine-2-thiones Via Radical Reaction And Studies On The Eletrophilicity And Nucleophilicity Of Different Radicals

In the past years, radical reactions have been highly concerned by the organic chemists. Radical cyclization has become a useful method for synthesis medium size cyclic organic compounds under neutral conditions as it has many advantages compared with ionic reactions.The first part of this thesis is on the synthesis of 5-subsituted thiazolidine-2-thiones.Thiazolidine-2-thiones and their derivatives are widely-used building blocks in organic synthesis and pharmaceutical chemistry. Their structural analogues can also be found in biologically active compounds. However, more studies documented about the synthesis of 4-subsituted thiazolidine-2-thiones using vicinal aminoalkyl alcohols and synthesis of 5-subsituted thiazolidine-2-thiones using the same method was limited because of the lack of raw material. Herein, various dithiocarbamates were synthesized from N-substituted allylamines as raw materials within two simple steps. Dithiocarbamates and xanthates underwent the radical addition and cyclized to finally afford 5-substituted thiazolidine-2-thiones with dilauroyl peroxide (DLP) as an initiator. This method has common raw materials and mild conditions. We can synthesis products with different functional groups by changing the xanthates and the candidates are various.Moreover, the relationship of the structure and chemical property of organic compounds is one of the most important issues in organic chemistry. The eletrophilicity and nucleophilicity of different radicals were investigated in the competitive experiments of different xanthates in the radical addition with N-allyl phthalimides and allyl phenyl ether. The Hammett analysis revealed the both reactions are electrophilic addition. Also, the Hammett analysis of the synthesis of 5-subsituted thiazolidine-2-thiones supports the mechanism with experimental evidence.