“…It should be noted, however, that related arsaalkenes were studied by Weber already since 1996, and for instance, the acyclic diaminocarbene–arsinidene adduct [{(Me 2 N) 2 C}AsSiMe 3 ] was used for the preparation of the iron(II) complex [(η 5 -C 5 Me 5 )Fe(CO) 2 {AsC(NMe 2 ) 2 }] . The reactivity of this “metalloarsaalkene” was further studied toward carbonylmetal complexes, , and trimethylaluminum, -gallium, and -indium, and its alkylation, protonation, and silylation produced a series of cationic complexes of the type [(η 5 -C 5 Me 5 )Fe(CO) 2 {RAsC(NMe 2 ) 2 }] (R = Me, H, SiMe 3 ) . In 1997, the first N-heterocyclic carbene–arsinidene adducts [(IMes)AsR] ( 518a , R = Ph; 518b , R = C 6 F 5 ) were isolated by Arduengo from the reaction of IMes with hexaphenylcyclohexaarsane, (AsPh) 6 , or tetrakis(pentafluorophenyl)cyclotetraarsane, (AsC 6 F 5 ) 4 , respectively (Scheme ).…”