Development of more labile low electron count Co(i) sources: mild, catalytic functionalization of activated alkanes using a [(Cp*Co)₂-μ-(η⁴:η⁴-arene)] complex

Abstract

Catalytic transfer dehydrogenation of silyl protected amines, requiring sp(3) C-H bond activation, is mediated by a bridging arene complex of the type [(Cp*Co)(2)-μ-(η(4):η(4)-arene)] under mild conditions. Mechanistic and qualitative rate studies establish the compound as a more reactive Co(I) source when compared to other known Cp*Co(I) complexes.

The Stabilization of Three-Coordinate Formal Mn(0) Complex with NHC and Alkene Ligation

“…In addition, the capability of low-coordinate low-valent transition-metal complexes in activating C-H bonds could also partly make a contribution. 107,108 The formation of these monoalkenes hints at the contribution of the mangana(II)-cyclopropane form (B in Figure 7) in the canonical structures of the three-coordinate formal Mn(0) alkene complexes. Complex 1 can also react with H 2 (1 atm) at room temperature to give a Mn(II) alkyl complex ( 9) in 71% yield (Scheme 4).…”

Bis(silylenyl)‐ and Bis(germylenyl)‐Substituted Ferrocenes: Synthesis, Structure, and Catalytic Applications of Bidentate Silicon(II)–Cobalt Complexes

“…Reactions of CpCo precursors with bis(silylene) 3 afforded the desired bis(silylene) Co I complex 5 in 30 % yield (Scheme 3). [21] In the 29 Si NMR spectrum, the coordination of the bis(silylene) moieties to the Co atom leads to a drastic downfield shift of the resonance of 5 (d = 82.0 ppm) in (2), Ge2-C8 1.9774 (19), Ge1-N1 2.0261(16), Ge1-N2 2.0247(17), Ge2-N3 2.0402(15), Ge2-N4 2.0162(16); C1-Ge1-N1 96.62 (7), C1-Ge1-N2 94.45 (7), N1-Ge1-N2 64.86 (7), C8-Ge2-N3 94.92 (7), C8-Ge2-N4 97.16 (7), N3-Ge2-N4 64.59 (6).…”

Cobalt-catalysed site-selective intra- and intermolecular dehydrogenative amination of unactivated sp3 carbons

“…In contrast to this, Brookhart and co-workers reported intramolecular hydrogen transfer of cyclic amines in 2007 via an inner-sphere mechanism, in which a carbon–cobalt bond was formed by oxidative addition of a cobalt species to the α-sp 3 C–H bond ( Fig. 1b ) 36 37 38 39 40 .…”