Photochemical C(sp)–C(sp²) Bond Activation in Phosphaalkynes: A New Route to Reactive Terminal Cyaphido Complexes L_nM–C≡P

Abstract

The photochemical activation of the C(sp)−C(sp 2 ) bond in Pt(0)-η 2 -aryl-phosphaalkyne complexes leads selectively to coordination compounds of the type L n Pt(aryl)(CP). The oxidative addition reaction is a novel, clean, and atom-economic route for the synthesis of reactive terminal Pt(II)-cyaphido complexes, which can undergo [3 + 2] cycloaddition reactions with organic azides, yielding the corresponding Pt(II)-triazaphospholato complexes. The C−C bond cleavage reaction is thermodynamically uphill. Upon heating, the reverse and quantitative reductive elimination toward the Pt(0)-phosphaalkyne-π-complex is observed.

Reactivity of Sodium Pentaphospholide Na[cyclo‐P5] towards C≡E (E=C, N, P) Triple Bonds

“…Having proven that the pentaphospholide anion reacts with C≡N triple bonds, we consequently attempted the reaction between 1 and phosphaalkynes as a potential pathway towards barely explored 1,2,3,4‐tetraphospholide anions. In analogy to the use of benzonitrile, preference was given to the use of the kinetically stabilized Mes‐C≡P (Mes=mesityl) [22] …”

“…In analogy to the use of benzonitrile, preference was given to the use of the kinetically stabilized Mes-C�P (Mes = mesityl). [22] Interestingly, preliminary studies reveal that the sodium 2,5bismesityl-1,3,4-triphospholide anion 6 was formed in the reaction with 1 equiv. of Mes-C�P, rather than the anticipated 1,2,3,4-tetraphospholide.…”

Revealing the Role of the Cyaphide Ion as a Bridging Ligand in Heterometallic Complexes

“…Only a handful of metal cyaphido complexes have been reported, the vast majority of which exhibit terminal, κ C coordination (i.e. [M]−C≡P) [8–13] . The dearth of known cyaphido complexes is largely due to the fact that, until recently, there was not a widely applicable route available for their synthesis.…”

Syntheses of η1‐Alkyl‐η3‐Allyl‐η5‐Cyclopentadienyl Cobalt(III) Complexes and Their Use in Low‐temperature Atomic Layer Deposition of Cobalt‐Containing Thin Films

“…[4] Even more difficult is to activate an inert C(sp 3 )À C(sp 3 ) bond, which has no π bonding nearby and is usually surrounded by a compact CÀ H shell that disfavors the kinetics as compared to the CÀ H activation (Scheme 1d). [4][5] A strategy to activate such C(sp 3 )À C-(sp 3 ) bonds is to utilize the strain. Starting from those compounds with highly strained three-or four-membered rings, the release of ring strain facilitates the metal insertion into the inert CÀ C bonds.…”