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.