N ‐Heterocyclic Carbene and Cyclic (Alkyl)(amino)carbene Adducts of Germanium(IV) and Tin(IV) Chlorides and Organyl Chlorides

A study on the reactivity of N ‐heterocyclic carbenes (NHCs) and the cyclic (alkyl)(amino)carbene cAAC Me with selected germanium(IV) and tin(IV) chlorides and organyl chlorides is presented. The reactions of the NHCs Me 2 Im Me , i Pr 2 Im Me and Dipp 2 Im with the methyl chlorides ECl 2 Me 2 afforded the adducts NHC ⋅ ECl 2 Me 2 (E=Ge ( 1 ), Sn ( 2 )), NHC=Me 2 Im Me ( a ), i Pr 2 Im Me ( b ), Dipp 2 Im ( c )). The reaction of Me 2 Im Me with GeCl 4 led to isolation of Me 2 Im Me  ⋅ GeCl 4 ( 3 ), the reaction of i Pr 2 Im Me with SnCl 4 in THF afforded the THF adduct i Pr 2 Im Me  ⋅ SnCl 4  ⋅ THF ( 4 ). Dipp 2 Im ⋅ GeCl 2 Me 2 ( 1 c ) isomerized into the backbone coordinated imidazolium salt [ a Dipp 2 Im ⋅ GeClMe 2 ][Cl] ( 5 ) upon thermal treatment. The reactions of cAAC Me with (i) ECl 2 R 2 (E=Ge, Sn) gave the adducts cAAC Me  ⋅ ECl 2 R 2 (R=Me: E=Ge ( 6 ); Sn ( 7 ); Ph: E=Ge ( 8 )), with (ii) GeClMe 3 and GeCl 4 the salts [cAAC Me  ⋅ GeMe 3 ][Cl] ( 9 ) and [cAAC Me Cl][GeCl 3 ] ( 10 ), and (iii) with SnCl 4 the salt [cAAC Me Cl][SnCl 3 ] ( 11 ) and the adduct cAAC Me  ⋅ SnCl 4 ( 12 ). Reduction of 2 a with KC 8 afforded the NHC‐stabilized stannylene Me 2 Im Me  ⋅ SnMe 2 13 , reduction of 7 with either KC 8 or 1,4‐bis‐(trimethylsilyl)‐1,4‐dihydropyrazin in the presence of SnCl 2 Me 2 yielded cAAC Me  ⋅ SnMe 2  ⋅ SnMe 2 Cl 2 ( 14 ).