Attempted reduction of a carbazolyl-diiodoalane

We report details of our attempts to reduce the bulky carbazolyl diiodoalane [R-AlI 2 ]. The reducing agents employed include KC 8 , Cp* 2 Co and the Mg( i ) compound [( Mes BDI)Mg] 2 . The use of KC 8 allowed the spectroscopic observation of the alanediyl [R-Al]. With Cp* 2 Co as the reducing agent, the alanediyl [R-Al] was obtained as a crystalline material in low yield, but paramagnetic impurities remained. When diiodoalane [R-AlI 2 ] was treated with [( Mes BDI)Mg] 2 , no reduction but a 2 : 1 addition was observed. A carbazolyl-diiodoalane was prepared and subjected to reducing conditions with KC 8 , Mg( i ) compounds, or Cp* 2 Co.