Efficient Synthesis of 1,5-Disubstituted Carbohydrazones Using K<sub>2</sub>CO<sub>3</sub> As a Carbonyl Donor
作者:Jun Wen、Chu-Ting Yang、Tao Jiang、Sheng Hu、Tong-Zai Yang、Xiao-Lin Wang
DOI:10.1021/ol500732c
日期:2014.5.2
A novel reaction that generates 1,5-disubstituted carbohydrazones via the carbonylation of tosylhydrazones has been developed. For the first time, the inexpensive, readily available, environmentally friendly, and nongaseous potassium carbonate is used as the carbonyl donor for the transformation. The reaction system exhibited tolerance with various functional groups and affords the desired products
Two pyrrole tosylhydrazones, 1H-pyrrole-2-tosylhydrazone (PT) and ethyl 3,5-dimethyl-4-(1-(2-tosylhydrazono)ethyl)-1H-pyrrole-2-carboxylate (EDTEPC) have been synthesized and characterized by various spectroscopic techniques. All calculations have been performed using B3LYP functional and 6-31G(d,p) basis set. The result of hydrogen bonding is obvious in H-1 NMR and FT-IR due to down field chemical shift and vibrational red shift to pyrrole N-H proton, respectively. The red shift in both the proton donor (pyrrole N-H) and proton acceptor (S=O) group designates presence of intermolecular classical hydrogen bonding N-H center dot center dot center dot O. The binding energy of dimer formation is calculated as 13.12, 14.12 kcal/mol, after correction in basis set superposition error (BSSE). Topological parameters indicate the weaker interactions presents in the molecules. The global electrophilicity index (omega = 2.54, 2.28 eV) shows that PT and EDTEPC molecules are strong electrophile. The local reactivity descriptors analyses are performed to determine the reactive sites within the FT and EDTEPC. Computed first hyperpolarizability (beta(0) = 6.50/8.38 x 10(-30) esu) of FT and EDTEPC indicates non-linear optical (NLO) response of the molecules. (C) 2014 Elsevier B.V. All rights reserved.