A Lead(II) Substituted Triplet Carbene.

Reaction of the pincer-type ligand L supported complex [LPbBr][BArF] () with Li[(C(═N)TMS)] furnishes [LPb(C(═N)TMS)][BArF] (). Diazo-compound eliminates dinitrogen upon irradiation affording formal plumba-alkyne , which persists in cold fluoroarene solutions. Variable temperature UV/Vis and NMR spectroscopies in combination with quantum-chemical calculations identify as a metal-substituted triplet carbene.

Synthesis and Modular Reactivity of Low Valent Al/Zn Heterobimetallics Supported by Common Monodentate Amides.

Recent advances on low valent main group metal chemistry have shown the excellent potential of heterobimetallic complexes derived from Al(I) to promote cooperative small molecule activation processes. A signature feature of these complexes is the use of bulky chelating ligands which act as spectators providing kinetic stabilization to their highly reactive Al-M bonds. Here we report the synthesis of novel Al/Zn bimetallics prepared by the selective formal insertion of AlCp* into the Zn-N bond of the utility zinc amides ZnR (R=HMDS, hexamethyldisilazide; or TMP, 2,2,6,6-tetramethylpiperidide).

Triphosphiranes as phosphinidene-transfer agents - synthesis of regular and chelating NHC phosphinidene adducts.

In this contribution we describe the general use of aryl-substituted triphosphiranes (ArP; Ar = Mes, Dip, Tip) as phosphinidene transfer reagents towards N-heterocyclic carbenes (NHCs) to give a library of twelve N-heterocyclic carbene phosphinidene adducts of the type ArPNHC (NHCPs), in which the NHCs have varying steric profiles, allowing a systematic evaluation of their structural and NMR-spectroscopic properties. In the next series of experiments we utilized 1,3- and 1,4-phenylene bridged bis-NHCs to access a new class of chelating bis(NHCP)s, of which three derivatives could be structurally characterized. The 1,4-phenylene derivatives were shown to be susceptible to P-C bond cleavage when irradiated with an LED (396 nm), providing a rare example of phosphinidene release from NHCPs.

Swift C-C bond insertion by a 12-electron palladium(0) surrogate.

The selective activation of C-C bonds holds vast promise for catalysis. So far, research has been primarily directed at rhodium and nickel under harsh reaction conditions. Herein, we report C-C insertion reactions of a 12-electron palladium(0) surrogate stabilized by a cyclic(alkyl)(amino) carbene (CAAC) ligand.