Studies on Poly(3,4-dimethyl-5-vinylthiazolium) Iodide Catalyzed Organic Reactions

Abstract

Part I. Various Synthetic Strategies using Poly(3,4-dimethyl-5-vinylthiazolium) Iodide as Catalyst<br/> Chapter 2. Hydrothiolation of Alkenes and Alkynes Catalyzed by 3,4-Dimethyl-5-vinylthiazolium Iodide and Poly(3,4-dimethyl-5-vinyl-thiazolium) Iodide Hydrothiolation reaction that is highly selective anti-Markovnikov addition of thiols to unsaturated carbon-carbon bonds has been developed using 3,4-dimethyl-5-vinylthiazolium iodide or its polymer, poly(3,4-dimethyl-5-vinylthiazolium) iodide as catalyst. A plausible mechanism involving a new model was confirmed by DFT calculations.<br/> <br/> Chapter 3. Synthesis of Benzothiazoles from 2-Aminobenzenethiols in the Presence of a Reusable Polythiazolium Precatalyst under Atmospheric Pressure of Carbon Dioxide Poly(3,4-dimethyl-5-vinylthiazolium) iodide based organocatalytic system could display activities in the cyclization of 2-aminobenzenethiols to benzothiazole in the presence of phenyl silane, 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU), and 1 atm of carbon dioxide. The polymer catalyst reused 7 times in the cyclization reaction without any lose of activities.<br/> <br/> Chapter 4. Transition-Metal-Free Poly(thiazolium) Iodide/1,8-Diazabicyclo[5.4.0]undec-7-ene/Phenazine Catalyzed Esterification of Aldehydes with Alcohols Esterification reactions of aldehydes with alcohols proceed using poly(3,4-dimethyl-5-vinylthiazolium) iodide and phenazine as an oxidant. The reaction performed under mild conditions, i. e. relatively low temperature (40 oC), reusable catalyst, and oxidant.<br/> <br/> Part II. Studies on Silver/NBS Catalyzed Organic Reaction<br/> Chapter 5. Silver/NBS- Catalyzed Synthesis of α-Alkylated Aryl Ketones from Internal Alkynes and Benzyl Alcohols via Ether Intermediates α-Alkylated aryl ketones with a tertiary carbon center were synthesized from internal alkynes and benzyl alcohols using NBS and silver as respective catalysts. A plausible mechanism involving an ether intermediate is proposed based on reasonable experiments.<br/>