Preparation, Structure and Reactions of Novel Tellurium-Containing Heterocycles

1. 1-benzotellurepines是一种新型的七元杂环化合物，以t-BuLi处理，然后加入金属试剂（Cl_2SnBu_2，Cl_2SbPh和Cl_2SiMe_2），通过碲-锂交换反应，一锅法分别得到相应的1-benzostannepines，1-benzostibepines和1-benzosilepines.以（Z）-1-（邻溴苯基）丁-1-烯-3-炔为原料，通过锡-锑和锡-硼交换反应，可将1-苯并锡酮分别转化为1-苯并锑酮和1-苯并硼酮，产率中等至较高.研究了由硒代色烯-4-酮经硒代氯烯合成未取代和2-取代1-苯并硒代吡喃盐的一般方法.研究了稳定的1-苯并硒代吡喃鎓盐与几种亲核试剂的反应以及LiAlH_4的还原反应，并对1-苯并碲代吡喃鎓盐的反应行为进行了比较. 1-苯并硒代吡喃鎓盐用烷基（苯基） ...更多信息 ）卤化镁在C-4位发生亲核加成反应，得到相应的2，4-二取代4 H-硒色烯，产率较高。所得硒色烯易于转化为2，4-二取代1-苯并硒吡喃盐.碲色烯-4-酮与几种Grignard试剂反应，分别以较好的产率得到4-取代的4-羟基-4H-碲色烯。得到的化合物很容易转化为2，4-二取代1-苯并碲吡喃盐。研究了邻乙炔苄基碲醚和邻乙炔苄基硒醇的区域选择性和立体定向分子内闭环反应。由邻乙炔基苄基溴与碲化氢钠（NaHTe）或硒化氢钠（NaHSe）反应生成的异碲并色烯和异硒并色烯分别与（Z）-1-亚甲基-2-碲氢化物和（Z）-1-亚甲基-2-硒氢化物一起生成。将所得异色烯和异色烯分别转化为相应的2-苯并吡喃四氟硼酸盐。还描述了2-叔丁基衍生物的X射线结构分析。少

1. The treatment of 1-benzotellurepines, novel seven-membered heterocycles, with t-BuLi followed by addition of a metal reagent (Cl_2SnBu_2, Cl_2SbPh and Cl_2SiMe_2) afforded the corresponding 1-benzostannepines, 1-benzostibepines and 1-benzosilepines, respectively, in one pot via the tellurium-lithium exchange.2. The 1-benzostannepines, which were prepared from (Z)-1-(o-bromophenyl) but-1-ene-3-ynes, were easily converted into the 1-benzostibepines and the 1-benzoborepines by tin-antimony and tin-boron exchange reactions in moderate to good yields, respectively.3. The general preparation of the unsubstituted and 2-substituted 1-benzoselenopyrylium salts from the selenochromen-4-ones via the selenochlomenes is investigated.4. The reactions of the stable 1-benzoselenopyrylium salts with several nucleophiles and also LiAlH_4 reduction are described ; comparison of the behavior of 1-benzotelluropyrylium salts is made.5. The treatment of the 1-benzoselenopyrylium salts with an alkyl(phenyl … More )magnesium halide resulted in nucleophilic addition at the C-4 position to give the corresponding 2,4-disubstituted 4H-selenochromenes in good yields, respectively. The obtained selenochromenes were men easily converted into the 2,4-disubstituted 1-benzoselenopyrylium salts.6. The treatment of the tellurochromen-4-ones with several Grignard reagents gave the 4-substituted 4-hydroxy-4H-tellurochromenes in good yields, respectively. The obtained compounds were readily transformed into the 2,4-disubstituted 1-benzotelluropyrylium salts.7. The regioselective and stereospecific intramolecular ring closure reactions of o-ethynylbenzyl tellurols and o-ethynylbenzyl selenols, which were readily. generated by the reaction of the o-ethynylbenzyl bromides with sodium hydrogen telluride (NaHTe) or sodium hydrogen selenide (NaHSe), produced the isotellurochromenes and isoselenochromenes together with (Z)-1-methylidene-2-tellurahidans and (Z)-1-methylidene-2-selenaindans, respectively. The obtained isochromenes and were transformed into the corresponding 2benzopyrylium tetratluoroborates, respectively. An X-ray structural analysis of the 2-tert-butyl denvatives is also described. Less