Fundamental Research for Developing Organotin Reagent

建立有机锡化合物作为合成试剂的效用的研究有以下新发现。（1）. Pd(O)催化偶联反应在杂芳烃中的应用。噻吩基和吡啶基溴易于与在Pd(PPh_3)_4存在下能与溴苯反应的有机锡试剂偶联，而不能与需要PdCl_2(Po-tol_3)_2催化剂才能与溴苯偶联的锡化合物偶联。噻吩基和吡啶基化合物与杂芳基溴的偶联为杂二芳基、杂三元芳基和杂季芳基的合成提供了良好的工具。（2）. 过渡金属配合物催化三元体系的偶联反应。在钯的催化下，有机锡和卤化物的偶联反应涉及到异腈和降冰片烯等第三组分的插入，分别产生亚胺和外显，顺式-2,3-二取代降冰片烷。(3)。在等量的TiCl_4存在下，羰基与羰基发生反应。反应后给予-内酯水解处理。锡酰胺、2-（2-锡基）吡啶和n -锡基-对中氧丙烯酮的反应类似。反应通过金属转化进行，得到分子内N或0与Ti配位稳定的钛化合物。

Research to establish the utility of organotin compounds as synthetic reagents gave the following new findings. (1). Application of Pd(O) catalyzed coupling reaction to heteroaromatics. Thienyl and pyridyl bromide were fond to couple with organotin reagents which can react with bromobenzene in the presence of Pd(PPh_3)_4, but not with those tin compounds which need the catalyst PdCl_2(Po-tol_3)_2 for the coupling with bromobenzene. The coupling of thienyl and pyridyltin compounds with heteroaryl bromides provides good tools for syntheses of heterobiaryls, heteroteraryls, and heteroquateraryls. (2). Coupling reactions of temary systems catalyzed by transition metal complexes. Coupling reactions of organotins and halides involving insertion of third components such as isonitrile and norbornene were found to take place under catalysis of palladium, giving imines and exo,cis-2,3-disubstituted norbomane, respectively. (3). Addition to carbonyls via transmetalation with TiCl_4.2-Stannylcarbonylates were found to react with aldehydes in the presence of equimolar amount of TiCl_4. The reaction giving gamma-lactones after hydrolytic treatment. Stannylamide, 2-(2-stannyl)pyridine and N-stannyl-p- medioxypropiophenone reacted similarly. The reaction proceeds via transmetalation giving titanium compounds stabilized by intramolecular coordination of N or 0 to Ti.