Donor-acceptor-stabilised germanium analogues of acid chloride, ester, and acyl pyrrole compounds: synthesis and reactivity.

Germaacid chloride, germaester, and N-germaacyl pyrrole compounds were not known previously. Therefore, donor-acceptor-stabilised germaacid chloride (i-Bu)(2)ATIGe(O)(Cl) → B(C(6)F(5))(3) (1), germaester (i-Bu)(2)ATIGe(O)(OSiPh(3)) → B(C(6)F(5))(3) (2), and N-germaacyl pyrrole (i-Bu)(2)ATIGe(O)(NC(4)H(4)) → B(C(6)F(5))(3) (3) compounds, with Cl-Ge[double bond, length as m-dash]O, Ph(3)SiO-Ge[double bond, length as m-dash]O, and C(4)H(4)N-Ge[double bond, length as m-dash]O moieties, respectively, are reported here. Germaacid chloride 1 reacts with PhCCLi, KOt-Bu, and RLi (R = Ph, Me) to afford donor-acceptor-stabilised germaynone (i-Bu)(2)ATIGe(O)(CCPh) → B(C(6)F(5))(3) (4), germaester (i-Bu)(2)ATIGe(O)(Ot-Bu) → B(C(6)F(5))(3) (5), and germanone (i-Bu)(2)ATIGe(O)(R) → B(C(6)F(5))(3) (R = Ph 6, Me 7) compounds, respectively. Interconversion between a germaester and a germaacid chloride is achieved; reaction of germaesters 2 and 5 with TMSCl gave germaacid chloride 1, and 1 reacted with Ph(3)SiOLi and KOt-Bu to produce germaesters 2 and 5. Reaction of N-germaacyl pyrrole 3 with thiophenol produced a donor-acceptor-stabilised germaacyl thioester (i-Bu)(2)ATIGe(O)(SPh) → B(C(6)F(5))(3) (10). Furthermore, the attempted syntheses of germaamides and germacarboxylic acids are also discussed.