Nickel and Platinum 1,2-Dibromoacenaphthylene Chemistry

Addition of 1,2-dibromoacenaphthylene to Ni(COD)2/2L gives the oxidative-addition
products trans-NiL2(Br)(2-bromoacenaphthylen-1-yl) (L = PEt3, PMe3). The intermediate
π-complex Ni(PMe3)2(η2-1,2-dibromoacenaphthylene) is isolated at short reaction times for
L = PMe3. An analogous complex, Pt(PEt3)2(η2-1,2-dibromoacenaphthylene), is formed in
the reaction of Pt(PEt3)4 with 1,2-dibromoacenaphthylene and must be heated to induce
oxidative-addition to cis-Pt(PEt3)2(Br)(2-bromoacenaphthylen-1-yl). Isomerization to the trans
isomer is achieved by further heating. Reduction of trans-Ni(PEt3)2(Br)(2-bromoacenaphthylen-1-yl) with Na/Hg gives two different products depending on the workup. One procedure
gives the Hg-bridged complex trans,trans-Ni(PEt3)2(Br)(acenaphthylen-1,2-diyl)Hg(acenaphthylen-1,2-diyl)Ni(PEt3)2(Br), while another procedure gives an unidentified complex that
is also formed when the reduction is done with KC8. Reduction of trans-Ni(PEt3)2(Br)(2-bromoacenaphthylen-1-yl) with Na/Hg in the presence of alkynes yields fluoranthenes,
suggesting the formation of an acenaphthylyne complex, which couples with the alkynes. A
small amount of trans,trans-Pt(PEt3)2(Br)(acenaphthylen-1,2-diyl)Hg(acenaphthylen-1,2-diyl)Pt(PEt3)2(Br) is obtained from the reduction of cis-Pt(PEt3)2(Br)(2-bromoacenaphthylen-1-yl) with Na/Hg with trans-Pt(PEt3)2(Br)(2-bromoacenaphthylen-1-yl) as the major product.
Reduction of trans-Pt(PEt3)2(Br)(2-bromoacenaphthylen-1-yl) with KC8 results in debromination of the acenaphthylenyl ring.

将1,2-二溴苊烯（1,2-dibromoacenaphthylene）与Ni(COD)2/2L混合，可得到氧化加成产物反式-NiL₂(Br)(2-溴苊烯-1-基)（trans-NiL₂(Br)(2-bromoacenaphthylen-1-yl)，其中L为PEt3、PMe3）。当L为PMe3时，可在反应初期分离得到中间体π配合物Ni(PMe3)₂(η²-1,2-二溴苊烯)。Pt(PEt3)4与1,2-二溴苊烯的反应可生成类似配合物Pt(PEt3)₂(η²-1,2-二溴苊烯)，该配合物需经加热才能发生氧化加成，转化为顺式-Pt(PEt3)₂(Br)(2-溴苊烯-1-基)；继续加热可使其异构为反式异构体。采用钠汞齐（Na/Hg）还原反式-Ni(PEt3)₂(Br)(2-溴苊烯-1-基)时，后续后处理方式不同会得到两种不同产物：其中一种方法可得到汞桥联配合物trans,trans-Ni(PEt3)₂(Br)(苊烯-1,2-二基)Hg(苊烯-1,2-二基)Ni(PEt3)₂(Br)，另一种方法则得到一种未鉴定的配合物，该产物在使用八石墨化钾（KC8）进行还原时也会生成。在炔烃存在下用钠汞齐还原反式-Ni(PEt3)₂(Br)(2-溴苊烯-1-基)，可得到荧蒽（fluoranthenes），这表明反应中生成了苊炔配合物，该配合物可与炔烃发生偶联反应。采用钠汞齐还原顺式-Pt(PEt3)₂(Br)(2-溴苊烯-1-基)，可得到少量trans,trans-Pt(PEt3)₂(Br)(苊烯-1,2-二基)Hg(苊烯-1,2-二基)Pt(PEt3)₂(Br)，主产物为反式-Pt(PEt3)₂(Br)(2-溴苊烯-1-基)。采用八石墨化钾（KC8）还原反式-Pt(PEt3)₂(Br)(2-溴苊烯-1-基)，会使苊烯基环发生脱溴反应。