Vinylgallium and Alkyllithium Compounds: Transmetalation and Generation of Oligolithium Cages

Vinylgallium compounds [C 6 H 6− n {(H)CC(SiR 2 R′)GaR′′ 2 } n ] ( 3 , R=Ph, Me; R′=Ph, Me; R′′= t Bu, Et; n =1, 2) are easily accessible by hydrogallation of the corresponding alkynylbenzene derivatives with HGaCl 2 and subsequent reaction with alkyllithium derivatives. Treatment of 3 with an excess amount of tert ‐butyl‐ or ethyllithium yielded by transmetalation and ortho ‐deprotonation of the aromatic rings the unprecedented solvent‐free oligolithium cluster compounds [{(C 6 H 4 Li)HCC(SiPh 3 )Li} 2 ( t BuLi) 2 ] ( 4 ), [{(C 6 H 4 Li)HCC(SiPh 2 Me)Li} 4 ] ( 5 ) and [{(C 6 H 3 Li){HCC(SiMe 3 )Li} 2 } 3 ] ( 6 ) in moderate yields. Their solid‐state structures revealed the presence of unique molecular lithium clusters with 6, 8, or 9 lithium atoms that may be derived from two edge‐sharing Li 4 tetrahedra ( 4 ), three Li 4 tetrahedra in a chain joined by two common edges ( 5 ) or a tricapped trigonal prism of lithium atoms ( 6 ).