INSERTION REACTIONS OF BENZYNE-NICKEL(O) COMPLEXES WITH ACETYLENES
INSERTION REACTIONS OF BENZYNE-NICKEL(O) COMPLEXES WITH ACETYLENES
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DOI：
10.1021/om00003a029
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发表时间：
1995-03-01
期刊：
影响因子：
2.8
通讯作者：
WENGER, E
中科院分区：
文献类型：
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作者：
BENNETT, MA;WENGER, E
含有 eta(2)-4,5-二氟苯炔、Ni((1,2-eta)-4,5-F2C6H2)(PEt(3))(2) (10) 和 Ni((1,2-eta)-4,5-F2C6H2)(dcpe) (11; dcpe = 1,2-双(二环己基膦基)乙烷，Cy(2)PCH(2)-CH(2)PCy(2))通过适当的(2-卤代芳基)镍(II)卤化物的碱金属还原合成。光谱测量（C-13 NMR、FAB-MS）表明，10、11 和母体苯炔络合物 Ni((1,2-eta)-C6H4)(PEt(3))(2) (2) 是单体，类似于结构特征物质 Ni((1,2-eta)-C6H4)(Cy(2)PCH(2)CH(2)PCy(2))。配合物2和10在室温下与PEt(3)进行快速分子间交换，并通过双插入金属-苯炔键与二取代乙炔反应，形成1,2,3,4-四取代萘。与亲电乙炔（MeO(2)CC(2)CO(2)Me、MeC(2) . CO(2)Me、HC(2)CO(2)Me 和 CF3C2CF3）也会形成芳香环三聚体；特殊的是，六氟丁-2-炔还可以与10个由两个苯炔单元和乙炔衍生的菲反应。不对称乙炔叔丁基乙炔和2-丁炔酸甲酯在所得萘中产生良好的区域选择性，有利的异构体非常依赖于取代基的空间和电子影响。 dcpe 配合物与乙炔的反应类似，但反应更慢，并且与 MeO(2)CC(2)CO(2)Me 可以观察到单插入配合物 Ni{C(CO(2)Me)=C(CO(2)Me)C(6)H(2)R(2)-o}(dcpe) (R = H, F)。
Complexes of nickel(0) containing eta(2)-4,5-difluorobenzyne, Ni((1,2-eta)-4,5-F2C6H2)(PEt(3))(2) (10) and Ni((1,2-eta)-4,5-F2C6H2)(dcpe) (11; dcpe = 1,2-bis(dicyclohexylphosphino)ethane, Cy(2)PCH(2)-CH(2)PCy(2)) have been synthesized by alkali-metal reduction of the appropriate (2-halo-genoaryl)nickel(II) halides. Spectroscopic measurements (C-13 NMR, FAB-MS) indicate that 10, 11, and the parent benzyne complex Ni((1,2-eta)-C6H4)(PEt(3))(2) (2) are monomeric, analogous to the structurally characterized species Ni((1,2-eta)-C6H4)(Cy(2)PCH(2)CH(2)PCy(2)). Complexes 2 and 10 undergo rapid intermolecular exchange with PEt(3) at room temperature and react with disubstituted acetylenes by double insertion into the metal-benzyne bond to form 1,2,3,4-tetrasubstituted naphthalenes. With electrophilic acetylenes (MeO(2)CC(2)CO(2)Me, MeC(2) . CO(2)Me, HC(2)CO(2)Me, and CF3C2CF3) an aromatic cyclotrimer is also formed; exceptionally, hexafluorobut-2-yne also gives with 10 a phenanthrene derived from two benzyne units and the acetylene. The unsymmetrical acetylenes tert-butylacetylene and methyl 2-butynoate give rise to good regioselectivity in the resulting naphthalenes, the favored isomers being very dependent on the steric and electronic influence of the substituents. The dcpe complexes react similarly but more slowly with acetylenes, and with MeO(2)CC(2)CO(2)Me the monoinsertion complexes Ni{C(CO(2)Me)=C(CO(2)Me)C(6)H(2)R(2)-o}(dcpe) (R = H, F) can be observed.