No abstract

Reactions of three equivalents of LGa {L=HC[C(Me)N(2,6-iPr C H )] } with SbX (X=F, Cl, Br, I) proceed with insertion into the Sb-X bond, elimination of LGaX , and formation of LGaSbGa(X)L (X=F 1, Cl 2, Br 3, I 4) containing a Ga=Sb double bond. In contrast, the 2:1 molar ratio reaction of LGa and SbCl initially gives the twofold insertion product [L(Cl)Ga] SbCl 7, which could not be isolated due to its strong tendency toward elimination of LGaCl and formation of distibene [L(Cl)GaSb] 5 at 25 °C or cyclotristibine [L(Cl)GaSb] 6 at 8 °C. The formation of 1-6 can be rationalized by formation of the Ga-substituted stibinidene L(X)GaSb as reaction intermediate.

Reactions of two equivalents of LGa {L = HC[C(Me)NAr] 2 ; Ar = 2,6-iPr 2 -C 6 H 3 } with SbX 3 (X = Cl, Br) yield double-inserted products (LGaX) 2 SbX (X = Cl 1, Br 2), which were isolated at -40°C. Warming solutions of 1 and 2 to ambient temperature results in intramolecular elimination of LGaX 2 and formation of Ga-substituted stibinidenes L(X)GaSb as reaction intermediates, which were stabilized by coordination of strong σ-donating carbenes. Four carbene-stabilized stibinidenes Me CAAC-SbGa(X)L { Me CAAC = [H 2 C(CMe 2 ) 2 NAr]C, Ar = 2,6-iPr 2 -C 6 H 3 , X = Cl 3, Br 4} and IDipp-SbGa(X)L {IDipp = 1,3- [a] 1669 Scheme 3. Thermal treatment of isolated samples of 1 and reactions with one equivalent of LGa, yielding cyclotristibines, distibines, and gallastibenes.

Oxidative addition reactions of gallanediyl LGa and AsX3 yield gallaarsenes LGaAsGa(Cl)L (X = Cl 1; Br 2) with a Ga–As double bond.

The dative Pd!Bi nteractioni naseries of R DPB R' Pd 0 and Pd II complexes (R DPB R' = (o-PR 2 C 6 H 4) 2 BR', diphosphinoborane) was analyzed using XRD, 11 BNMR spectroscopy and NBO/NLMOc alculations.T he borane acceptor discriminates betweenthe oxidation state Pd II and Pd 0 ,s tabilizing the latter.R eaction of lithium amides with [(R DPB R')Pd II (4-NO 2 C 6 H 4)I] chemoselectivelyy ields the CÀNc oupling product. DFT modelling indicates no significant impact of Pd II !B coordination on the inner-spherer eductivee limination rate.