| Sonogashira cross-coupling reaction is the most effective way to form the C(sp~2)-C(sp)bond.Its products of diaryl acetylene compounds are also the important structural units in organic synthesis.Because the triple bond of carbon can take place nucleophilic addition with most of nucleophilic reagents catalyzed by transition metal,which is not only the key effective method to form C-C,C-N,C-O,and C-S bonds,but also is an important,efficient and convenient method for the construction of heterocylces containing nitrogen,oxygen and sulfur atoms.A review about C(sp~2)-C(sp)coupling reaction with phenylacetylene,and its subsequent nucleophilic addition was summarized briefly in first chapter of this article.In the second chapter,a series of(E)-12-benzylideneisoindolo[1,2-b]quinazolin-10(12H)-ones(3a-3r)were synthesized in high yields via a "one-pot" procedure using 2-(2-bromophenyl)quinazolin-4(3H)-one and phenylethyne as the reactants,Cs2CO3 as a base and CuI as a catalyst in 1,4-dioxane.This domino type reaction included a Sonogashira cross-coupling reaction and hydroxylation reaction of alkyne.The structures of the products were characterized by 1H NMR,IR,13 C NMR and HRMS.The experimental results indicated that it was the hydrogen of amide attending the addition reaction of alkyne,a possible mechanism of the reaction was proposed and further confirmed by controlled experimental.In the third chapter,four reactions between phenyl acetylene and 2-(2-bromine phenyl)imidazoles were studied.2-(2-bromophenyl)-4,5-diphenyl-1H-imidazole,2-(2-Bromophenyl)-1H-phenanthro[9,10-d]imidazole,2-(2-bromophenyl)-1H-imidazo [4,5-f][1,10]phenanthroline and 8-(2-bromophenyl)-7H-acenaphtho[1,2-d]imidazole were performed as raw materials to react with phenylacetylene in DMSO,using Cs2CO3 as a base,Cu I as a catalyst,respectively.The C(sp~2)-C(sp)and C-N were constructed by continuous Sonogashira cross-coupling and hydroxylation reaction of alkyne,which obtained four series of imidazoisoquinoline derivatives(including phenanthro[9',10':4,5] imidazo[2,1-a]isoquinolines,imidazo[2,1-a]isoquinoline,isoquinolino[2',1':1,2]imidazo [4,5-f][1,10]phenanthroline and acenaphtho[1',2':4,5]imidazo[2,1-a]isoquinoline).The structures were evidenced by NMR,IR,and HRMS.The structures of the compounds 5d,11 d were further confirmed by X-ray single crystal diffraction analysis.And there is a similar reaction mechanism in the reaction with comparing to that of chapter two,the only a difference is that the imine of imidazole ring was participated in the acetylene hydroamination reaction.In the last chapter,the reactions between phenylacetylene and 2-bromo-Nphenylbenzothioamides were investigated.Beasuse the imide sulfide anion could be generated from benzothioamide in the presence of base,which could participate in acetylene hydroamination reaction as those of NH in original amides or imidazoles.Experimental results showed that the sulfur anion of the molecules participated in the acetylene hydroamination reaction,and N,3-diphenyl-1H-isothiochromen-1-imine derivatives were chemoselectively obtained in the desired reaction of 2-bromo-N-phenylbenzothioamide and phenylacetylene(Cs2CO3 as a base,N,N-dimethylacetamide as a solvent,CuI as a catalyst).According to the experimental results,we put forward a possible reaction mechanism that is Sonogashira coupling at first step,then isomerization of thioamide to sulfide anion,finally the hydroamination reaction of acetylene.The above experimental results show that the reaction of "one pot" catalyzed by Cu I could efficiently realize C(sp~2)-C(sp)Sonogashira coupling reaction,then the hydroxylation of alkyne with N or S-atoms,which could produce polycyclic heterocyclic compounds such as isoindoloquinazoline,imidazoisoquinoline,and isothiochromene.All the products' structures were finally charaterized by NMR,HR-MS and IR spectra.Of which compounds3 r,5d,11 d were further confirmed by X-ray single crystal diffraction analysis. |
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