Synthesis Of Parazoles And Pyrroles Based On Active Al-kyne-involved Multicomponent Reactions

The discourse includes four parts.The first part shows that, with the emergence of the concepts of “atom economy”and “green chemistry”, and higher demands of the synthesis, some new synthetic me-thodologies and ideas, including multicomponent one-pot tandem strategy and directfunctionalizatin of sp3C-H bond, have been arised rapiedly. In addition, this part intro-duces the multicomponent tandem reactions involving acetylenedicarboxylate. The sig-nificance and base of the selection of the subject, the original points and the researchtechniques were provided.In the second part, an efficient and practical methodology of selectively divergentsynthesis of arylidene pyrazolones and C-tethered bispyrazol-5-ols via mutlicomponentdomino reactions of acetylenedicarboxylates, phenylhydrazine and aromatic aldehydeshas been developed. The electron-donating aryl groups (EDAG)-attached aldehydes re-sulted in the pyrazolone skeleton, whereas the electron-withdrawing aryl groups(EWAG) led to the C-tethered bispyrazol-5-ols with simultaneous formation of two newpyrazole rings.In the third part, a novel multi-component reaction for the synthesis of pyrazoli-zated indoles has been established. During the reaction process, activation of allylic sp3C-H bond and introduction of a pyrazole ring which was generated in situ direct to theactived allylic carbon atom can be easily achieved in a metal-free and one-pot operation.Five new bonds and two significant rings with broad potential biological activity areformed in a single reaction without the need to isolate intermediates. Consequently, theprinciples of “atom economy” and “green chemistry” are performed to a large extent.The forth part shows the application of microwave irradiation (MWI) in organicsynthesis. This part involves one-pot, multicomponent domino synthesis of3-hydroxy-1H-pyrrol-2(5H)-one derivatives, stating from acetylenedicarboxylates, dif-ferent amines and aldehydes, under microwave irradiation during just one step. Thereaction is very fast and performs the principles of “atom economy” and “green chemi-stry” to a large extent due to each component participates fully in the reaction. This me-thodology of synthesis of3-hydroxy-1H-pyrrol-2(5H)-one derivatives via mutlicompo-nent domino reactions are suitable for different acetylenedicarboxylates, amines andaldehydes. The structures of the products were determined by IR,1H NMR. Furthermore, thestructures of some products were confirmed X-ray analysis. The microwave-assistedreactions mentioned above have advantages of shorter reaction time, higher yields andeasier work-up as well as environment friendly.