Syntheses and Reactions of Derivatives of (Pyrrolylaldiminato)germanium(II) and -Aluminum(III)

(Pyrrolylaldiminato)germanium(II) chloride, LGeCl ( 1 ), was prepared by reacting LLi (L = 2-(ArN═CH)-5- t BuC 4 H 2 N; Ar = 2,6- i Pr 2 C 6 H 3 ) with 1 equiv of GeCl 2 ·(dioxane). Treatment of LGeCl ( 1 ) with KO t Bu or LiN(H)Ar yielded LGeR (R = O t Bu ( 2 ), N(H)Ar ( 3 )) by halide metathesis. (Pyrrolylaldiminato)methylaluminum chloride, LAlMe(Cl) ( 4 ), was obtained from the reaction of LLi and MeAlCl 2 or by treating LH with Me 2 AlCl in toluene. Treatment of LH with Me 2 AlCl or AlCl 3 in Et 2 O at −18 °C resulted in the 1:1 adducts LH·AlMe 2 Cl ( 5 ) and LH·AlCl 3 ( 5 ′), respectively. Further reaction of 4 with 2 equiv of LiNEt 2 led to the insertion of the NEt 2 group into the C═N bond together with the elimination of LiCl, to afford L′(NEt 2 )AlMe(NEt 2 )Li(THF) ( 6 ). Similarly, treatment of 4 with 2 equiv of LiPPh 2 (THF) 2 gave L′(PPh 2 )AlMe(OC 4 H 8 -PPh 2 )Li(THF) 2 ( 7 ) accompanied by ring opening of THF. Single-crystal X-ray structure determinations revealed that 3 and 4 each contained enantiomeric pairs, while 6 and 7 each adopted a single enantiomer.