Research news, Jan. 1st, 2014.
Isolable and Well-Defined Butadienyl Organocopper(I) Aggregates: Facile Synthesis, Structural Characterization and Reaction Chemistry
Weizhi Geng, Junnian Wei, Wen-Xiong Zhang, and Zhenfeng Xi*
J. Am. Chem. Soc. 2014, DOI: 10.1021/ja4114243
Four types of alkenyl organocopper(I) aggregates linked by 1,3-butadienyl and/or 1,3,5,7-octatetraenyl moieties were high selectively realized in good isolated yields. All these organocopper(I) aggregates were structurally characterized by single-crystal X-ray structural analysis. These unprecedented aggregates, stabilized by multiply Cu-Cu interactions and the conjugated 1,3-butadienyl or 1,3,5,7-octatetraenyl bridges, could undergo controlled structural transformations. The 1,4-dicopper 1,3-butadienyl aggregate 3 could be efficiently transformed to aggregate 2, while LiI could disaggregate the 1,3-butadienyl-1,3,5,7-octatetraenyl aggregate 4 to 1,3,5,7-octatetraenyl aggregate 5 and 1,3-butadienyl aggregate 2. Preliminary reaction chemistry and synthetic applications of these organocopper(I) aggregates were also investigated.
Organocopper compounds are structurally very interesting and synthetically very useful. Isolable and structurally well-defined alkenyl organocopper(I) compounds are basically unknown. It is the cooperative-stabilizing ability of our dilithio reagents that make these organocopper compounds available, in which the butadienyl bridge constructs a favorable structural environment for achieving Cu-Cu interactions to stabilize the alkenyl-dicopper compounds.