Transition metals in organic synthesis: highlights for the year 1996

Indenyl complexes of Group 9 metals: Synthetic and catalytic chemistry

Nickel(0)-Catalyzed Efficient 2:2 Double-Cycloaddition of Monoynes with N-Substituted Maleimides To Form Bicyclo[2.2.2]oct-7-enes and Its Development into Nickel(0)-Catalyzed Double-Cycloaddition Copolymerization of Diynes with N-Substituted Maleimides to Poly(bicyclo[2.2.2]oct-7-ene)s†

Nickel(0)-catalyzed double-cycloaddition reactions of phenylacetylene ( 1a ), 1-pentyne ( 1b ), and 3-hexyne ( 8a ) with N -phenyl- ( 2a ), N -octyl- ( 2b ), and N -ethylmaleimide ( 2c ) to afford bicyclo[2.2.2]oct-7-enes were investigated in THF. The Ni(CO) 2 (PPh 3 ) 2 -catalyzed 2b / 1a =2 reaction produced bicyclo[2.2.2]oct-7-ene 6ab chemo- and regioselectively in excellent yield. The 2b / 1b =2 reaction gave two regioisomeric bicyclo[2.2.2]oct-7-enes in high yield. Internal monoyne 8a also underwent the double-cycloaddition with 2a or 2c . X-ray structural analysis of the 8a – 2c cycloadduct demonstrated an exo , exo -stereochemistry of its bicyclo[2.2.2]oct-7-ene ring. On the basis of these results, nickel(0)-catalyzed diyne-maleimide double-cycloaddition copolymerization was examined. 1,4-Diethynylbenzene ( 10a ) copolymerized with 2b to produce a poly(bicyclo[2.2.2]oct-7-ene) with the molecular weight up to 35,000 while 10a – 2a , c copolymerizations produced insoluble copolymers. 1,11-Dodecadiyne- 2a – c and 3,11-tetradecadiyne- 2a copolymerizations yielded soluble poly(bicyclo[2.2.2]oct-7-ene)s. A variety of poly(imide)s with complex structures were prepared by nickel(0)-catalyzed monoyne-dimaleimide and diyne-dimaleimide double-cycloaddition copolymerizations.

Nickel(0)-catalyzed monoyne-maleimide double-cycloaddition and its application to nickel(0)-catalyzed diyne-maleimide, monoyne-dimaleimide, and diyne-dimaleimide double-cycloaddition copolymerizations

https://journals.iucr.org/x/issues/2016/01/00/wm5256/wm5256.pdf

Tetsuo Tsuda

Papers

Cobalt-catalysed cycloaddition terpolymerisation of carbon monoxide with diynes and norbornadiene to form poly(enone)s