Chemistry World Conference

Sep 06-08, 2021 | Rome, Italy

Scopus Indexed Conference

Siaka Abdulfatai

Speaker for Chemistry 2020
Siaka Abdulfatai
Federal University Dutsin-Ma, Nigeria
Title : Mechanism of spiro-heterocycle formation: Density functional theory approach


Literature is hugely deficient in theoretical kinetic and thermodynamic data on formation mechanisms of some bioactive spiro-heterocycles.  Formation of 1’-((((aminoxy)carbonyl)amino)methyl)-2’-(1-hydroxynaphthalen-2-yl)-2’-methyl-1’,2’,5’,6’,7’-7a’-hexahydrospiro[indoline-3,3’pyrrolo[1,2-a]imidazol]-2-one was theoretically investigated using ab initio method. For more accurate result, density functional theory at B3LYP with 6-311+G** basis set was employed. There were bond length alterations (C9–N10, C9–C12, C13–N10 and C8–N10) as the interaction between the reacting species progressed through the stationary points to the product.  The HOMO–LUMO energy gap suggested that pyrrolidine-2-carboxylic acid (?E = –6.27 eV) acted as Lewis acid while indolin-2,3-dione (?E = –3.90 eV) acted as a Lewis base for the intermediate formation step. The formation of Van der Waals Complex 1 (VWC 1) step was computed to be exothermic (-72.95 kJmol-1) and slightly endergonic (+1.78 kJmol-1), while the transition step leading to the formation of transition state 1 has the rate constant, k, value of 1.87× ?10?^(-1) dm3mol-1s-1. From the mechanism of the reaction, the rate of formation of the product was found to be dependent on the isatin, [A] and pyrrolidine-2-carboxylic acid, [B] concentration by the expression (d[P])/dt=  (?k_2^2 k?_2^' k_1^')/(k_(2^' ) k_1 ?(k?_(-2)^'+ k_2)) [A][B]. 


Born to Mr. and Mrs Siaka, Abdulfatai obtained his primary education at Local Government Education Authority Obeiba Ihima, after which he proceeded to Okehi Community Secondary School Ikuehi Ihima for his secondary school certificate in 1996.  Siaka Abdulfatai obtained his Bachelor of Science (BSc) degree in Applied Chemistry from University of Jos, Nigeria in 2004.  He later went to Ahmadu Bello University for his Master of Science (MSc) and Doctor of Philosophy (Ph. D) degrees in Physical Chemistry in 2011 and 2017 respectively.  Abdulfatai is currently lecturing in the Department of Applied Chemistry of Federal University Dutsin-Ma Nigeria.  He is married with three children. 

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