Selective C-H Bond Activation by Group 7 and 8 Transition Metal Complexes and its Application to Organic Synthesis

本研究的目的是开发利用7和8族过渡金属配合物激活功能化有机物质的新型C-H键及其在选择性有机合成中的应用。在本研究中，成功地制备了新的铼、铁和钌配合物，可以顺利地产生反应性的配位不饱和物质。它们是ReH(C_2H_4)_2(PMe_2Ph)_3 (1), ReH(N_2)(PMe_2Ph)_4 (2), [MnMe_2(dmpe)_2]^+[AlMe_4]^- (3), [MnMe_2(dmpe)_2]^+[BPh_4]^- (4), RuH_2(PPh_3)_4 (5), Ru(C_2H_4)(PPh_3)_3 (6), Fe(N_2)(depe)_2(7)，配合物2,5和6与活性氢化合物反应得到具有烯醇酸阴离子配体的氢化物配合物。由α -氰羧酸酯衍生的烯酸酯配合物氰基与金属直接配位，留下高度亲核的烯酸酯部分。这些配合物分别与醛类和丙烯腈反应生成醛醇反应产物和迈克尔加成产物。5和6与2,4-戊二酮反应产生的烯醇酸复合物不与这些化合物反应。这些配合物2、5、6和由此制备的烯酸酯配合物以及Ru(cod)(cot)/PR_3体系都是这些反应的选择性催化剂。这些结果表明，本研究分离的烯酸酯配合物是活跃的反应中间体，支持了钌和铼催化醛醇和Michael型反应的高选择性。另一方面，烯基羧酸酯的C-H键氧化选择性地加入钌(0)，得到新的羟基烯基和羟基烯丙基配合物，这取决于所使用的酯。在后一种情况下，二烯羧酸酯型配合物是通过从sigma-烯丙基中间体中消除-氢而逐渐形成的。这些CH键活化反应的注册选择性可以通过钌产物的热力学稳定性来理解。在环境条件下，在铼上的配位α -氰酸酯与四氰乙烯之间发生了不寻常的烯烃复分解反应。该反应被认为是官能化烯烃的烯烃复分解的第一个例子。少

The objects of this research are development of novel C-H bond activation of functionalized organic substances using group 7 and 8 transition metal complexes and its application to selective organic syntheses. In this research, new rhenium, iron, and ruthenium complexes, which can smoothly produce reactive coordinatively unsaturated species, are successfully prepared. They are ReH(C_2H_4)_2(PMe_2Ph)_3 (1), ReH(N_2)(PMe_2Ph)_4 (2), [MnMe_2(dmpe)_2]^+[AlMe_4]^- (3), [MnMe_2(dmpe)_2]^+[BPh_4]^- (4), RuH_2(PPh_3)_4 (5), Ru(C_2H_4)(PPh_3)_3 (6), Fe(N_2)(depe)_2 (7), Complexes 2,5, and 6 react with active hydrogen compounds to give hydride complexes having an enolate anionic ligand. Enolate complexes derived from alpha-cyanocarboxylates have direct coordination of the cyano group to the metal leaving a highly nucleophlic enolate moiety. These complexes smoothly react with aldehydes and acrylonitrile to give aldol reaction and Michael addition products respectively. In contrast, enolate compl … More exes, which are produced by the reaction of 5 and 6 with 2,4- pentanedione, do not react with these compounds. All these complexes 2,5,6 and the enolate complexes thus prepared as well as Ru(cod)(cot)/PR_3 system act as selective catalysts of these reactions. These results indicate that the enolate complexes isolated in this research are active reaction intermediates, and support the unusually high selectivity of the ruthenium and rhenium catalyzed aldol and Michael type reactions.On the other hand, the C-H bonds of alkenecarboxylates oxidatively add selectively to ruthenium(0) to give new hydridoalkenyl and hydrido-pi-allyl type complexes, depending on the esters employed. In the latter case, dienecarboxylate type complexes are gradually formed by the beta-hydrogen elimination from a sigma-allyl intermediate. The regeiselectivity in these CH bond activation reactions can be understood by the thermodydamic stability of the ruthenim products.Unusual olefin metathesis reaction between coordinated alpha-cyanocinnamate on rhenium and tetracyanoethylene takes place under ambient conditions. The reaction is considered as the first example of olefin metathesis of functionalized olefins. Less