Synthesis and Reactions of Strucuturally New Intermediates of the Witting-type Reactions Contaning Group 13,14, and 15 Elements

1.第一个四配位的1，2-氧硼内酯是通过在18-冠-6存在下用KH处理相应的β-羟烷基二均三甲苯基硼烷而合成的。X射线晶体学分析表明它具有畸变的四面体结构。Therapy已经给出了相应的烯烃，表明它是硼-Witting反应的中间体。加热时，苯甲醛加合物的三甲基硅醚发生Witting型反应，生成相应的烯烃。2.以锗-Peterson反应的中间体β-羟烷基锗烷为原料，合成了一个含Martin配体的五配位2-苯基-1，2-氧锗烷。2-并给出了甲基衍生物。X射线衍射分析表明，它们具有畸变的三角双锥（TBP）结构。在烯烃形成反应发生之前，2-苯基和2-甲基-1，2-氧杂锗烷酰胺都观察到热异构化，动力学研究表明异构化通过彼此不同的机理进行。3.2，2，6，6-四苯基和2，2，6，6-四（对氯苯基）-1，5-二氧杂-4-氮杂-5-磷杂螺[3.3]庚烷是通过相应的二羟基氧化膦与阿佩尔试剂（Ph_3 P-CCI_4）的环合和脱水反应合成的。虽然它们不能分离，但已分离出后者的3，7-二甲基衍生物的三种非对映异构体。X-射线晶体学分析表明，两个非对映体具有扭曲的TBP结构，但一个具有扭曲的四棱锥结构。它们的理论值给出了两摩尔当量的相应烯烃。首次合成了五配位1，2-氮杂磷杂环丁烷类化合物，并首次观察到了C-顶端和N-赤道的假旋转异构体。这些结果已部分作为简短的通讯发表。

1.The first tetracoordinate 1,2-oxaboretanide has been synthesized by treatment of the corresponding beta-hydroxyalkyldimesitylborane with KH in the presence of 18-crown-6. The X-ray crystallographic analysis has shown that it has a distorted tetrahedral structure. Thermolysis has given the corresponding olefin, indicating that it is an intermediate of the boron-Witting reaction. On heating trimethylsilyl ether of benzaldehyde adduct undergoes the Witting-type reaction to give the corresponding olefin. 2.A pentacoordinate 2-Phenyl-1,2-oxagermetanide bearing the Martin ligand has been similarly obtained from the corresponding beta-hydroxyalkylgermane as an intermediate of the germanium-Peterson reaction. 2-Methyl derivative has also been given. The X-ray crystallographic analysis has shown that they have a distorted trigonal bipyramid (TBP) structure. Before olefin formation reaction takes place, thermal isomerization has been observed for both 2-phenyl and 2-methyl-1,2-oxagermetanides, kinetic study indicating that the isomerization proceeds via a different mechanism each other. 3.2,2,6,6-Tetraphenyl-and 2,2,6,6-tetrakis(p-chlorophenyl)-1,5-dioxa-4lambda^5-phoshaspiro[3.3]heptanes have been synthesized by the cyclization and dehydration reaction of the corresponding dihydroxyphosphine oxides with Appel reagent (Ph_3P-CCI_4). Although they not isolable, three diastereomers of 3,7-dimethyl derivative of the latter have been isolated. The X-ray crystallographic analysis has shown that two diastereomers have a distorted TBP structure, but one has a distorted tetragonal pyramid structure. Their thermolysis has given two molar equivalents of the corresponding olefin. The first example of pentacoordinate 1,2-azaphosphetidines has also been synthesized and C-apical and N-equatorial pseudorotamer has been observed for the first time. These results have been partially published as short communications.