O'Connor Joseph M, Closson Adam, Gantzel Peter
Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA.
J Am Chem Soc. 2002 Mar 20;124(11):2434-5. doi: 10.1021/ja0255296.
The bis(ethene) complex [(Tp)Ir(C(2)H(4))(2)] (3) undergoes reaction with dimethyl acetylenedicarboxylate (DMAD) in acetonitrile solvent at 60 degrees C to give the trispyrazolylborate metallacyclopent-2-ene complex [(Tp)Ir (CH(2)CH(2)C(CO(2)Me)=C(CO(2)Me))(NCMe)] (4). Spectroscopic analysis of a room-temperature reaction between 3 and DMAD in acetonitrile-d(3) provides evidence for the formation of an eta(2)-alkene/eta(2)-alkyne intermediate on the path to 4. The reaction of 3 with DMAD in THF solvent leads to the formation of the THF-ligated metallacyclopent-2-ene complex [(Tp)Ir(CH(2)CH(2)C(CO(2)Me)=C(CO(2)Me))(THF)] (5), which undergoes further reaction with DMAD at 60 degrees C in benzene to give [(Tp)Ir(C(CO(2)Me)=C(CO(2)Me)C(CO(2)Me)=C(CO(2)Me))(eta(2)-CH(2)=CH(2))] (6). Complex 4 was structurally characterized by X-ray crystallography.
双（乙烯）配合物[(Tp)Ir(C₂H₄)₂]（3）在60℃的乙腈溶剂中与二甲基乙炔二羧酸酯（DMAD）反应，生成三吡唑硼酸金属环戊 - 2 - 烯配合物[(Tp)Ir(CH₂CH₂C(CO₂Me)=C(CO₂Me))(NCMe)]（4）。在氘代乙腈中对3和DMAD在室温下的反应进行光谱分析，为在生成4的过程中形成η² - 烯烃/η² - 炔烃中间体提供了证据。3与DMAD在四氢呋喃（THF）溶剂中的反应导致生成THF配位的金属环戊 - 2 - 烯配合物[(Tp)Ir(CH₂CH₂C(CO₂Me)=C(CO₂Me))(THF)]（5），其在60℃的苯中与DMAD进一步反应生成[(Tp)Ir(C(CO₂Me)=C(CO₂Me)C(CO₂Me)=C(CO₂Me))(η² - CH₂=CH₂)]（6）。配合物4通过X射线晶体学进行了结构表征。
