Development of Novel Chiral Synthon by Using Cationic Palladium Complexes

三氟甲磺酸钯与2当量的三氟甲磺酸钯的反应。以二齿膦配体R_2P（CH_2）_nPR_2（n= 1，2，3）为配体，合成了阳离子三氟甲磺酸钯配合物L_2Pd^<2+>（OTf）_2。与4当量的反应用单齿膦配体R_3P与乙腈反应，得到阳离子钯配合物（R_3P）_（<4-n>CH_3CN）_nPd^（OTf）_2。根据膦的结构不同，这些配合物与乙腈的结构不同。例如，三正丁基膦可得到四丁基膦配合物，三三苯基膦或三叔丁基膦可得到三丁基膦配合物，（i-Pr）_3P和（c-Hex）_3P可得到两个膦配合物，它们在<31>乙腈溶液中以动态平衡混合物的形式存在。研究结果已在第45届<th>有机金属化学学术会议（1998年，东京）上发表，发现了双齿膦配体配合物对环戊二烯加氢磺化和聚合的催化作用，并正在探索其在硅氢化磺化反应中的应用。以光学活性的邻苯二磺酸为原料，合成了一种手性亚磺酸。

Reactions of palladium triflate with 2 equiv. of didentate phosphine ligands, R_2P(CH_2)_nPR_2 (n=1,2,3), afforded cationic palladium triflate complexes, L_2Pd^<2+>(OTf)_2, in high yields. Reactions with 4 equiv. of monodentate phosphines, R_3P, gave cationic palladium complexes with acetonitrile, (R_3P)_<4-n> (CH_3CN)_nPd^<2+>(OTf)_2. Depending on the structure of phosphines, structures of these complexes with acetonitrile were different. For example, the tetrakis(tributyl)phosphine complex was obtained in the case of tri(n-butyl)phosphine, and tris(triphenyl) or tris(tri t-butyl)phosphine comples were obtained in the case of Ph_3P or (t-Bu)_3P.The complexes with 2 phosphines were obtained from reactions with (i-Pr)_3P and (c-Hex)_3P.It is found by ^<31>P NMR studies on the obtained complexes that those complexes existed as dynamic equiriblium mixture in acetonitrile solutions. The results were reported in 45^<th> symposium for organometallic chemistry (1998, Tokyo).Catalytic natures of the complexes with didentate phosphine ligands toward hydroslufination and polymerization of cyclopentadiene were found. Application to hydrosilasulfination was under investigation. A chiral alkanesulfinic acid was prepared from optically active camphorsulfonic acid.