The application of polymer-bound carbonylcobalt(0) species in linker chemistry and catalysis

Abstract

Carbonylcobalt(0) species have been used as linkers between alkynes and a polymer support for the first time. The alkynes may be loaded indirectly onto a phosphine functionalised polymer via their hexacarbonyldicobalt(0) complex, or directly onto a cobalt coated polymer. The alkynes have been released either as alkynes, thus providing a traceless method of immobilising alkynes, or by reaction with an alkene to generate a cyclopentenone via the Pauson-Khand reaction. The cobalt coated polymers produced during this study were shown to catalyse the Pauson-Khand reaction.

A “Catch‐and‐Release” Protocol for Alkyne‐Tagged Molecules Based on a Resin‐Bound Cobalt Complex for Peptide Enrichment in Aqueous Media

“…The cobalt–phosphine complex 7 a and its alkyne complex 8 were characterised by IR spectroscopy. The IR absorptions of the carbonyl groups of the polymer‐supported complexes 7 a and 8 showed good correlation with those of [Co 2 (CO) 7 (PPh 3 )], the corresponding non‐polymer‐supported complex 4 and similar known cobalt complexes (see Figure S4 in the Supporting Information) 17c. 19, 26…”

“…We employed the TentaGel PS‐PEG (polystyrene‐polyethylene glycol) resin as it has been used as a polymer support for catalysts in aqueous media and is also compatible with organic solvents due to its good swelling ability. TentaGel®‐supported phosphine 6 was synthesised according to a reported procedure,24 and subsequently the brown phosphine–cobalt complex 7 a was prepared by mixing 6 and [Co 2 (CO) 8 ] in THF at room temperature 17c. 19 The reaction of cobalt complex 7 a supported on TentaGel with alkyne 1 (2 m M ) was carried out in aqueous HEPES buffer (pH 7.0)25 containing 0.5 % Triton X‐100.…”

“…Cobalt complex 7 a (10 mg, ∼0.23 mmol g −1 )17c, 19 pre‐washed with HEPES buffer (pH 7.0) was added to a solution of alkyne 1 (50 μ M , 1 mL) in HEPES buffer (pH 7.0) containing 150 m M NaCl, 10 m M HEPES‐Na, and 0.5 % Triton X‐100 at 4 °C. The mixture was rotated for 12 h at the same temperature, and then centrifuged.…”

Capture and release of alkyne-derivatized glycerophospholipids using cobalt chemistry

“…The alkyne-cobalt complex can be subsequently immobilized onto a solid-supported phosphine. It has been demonstrated that alkyne-cobalt complexes react selectively with triphenylphosphine (PPh 3 ) and solid-supported PPh 3 22–23. We envisioned using an approach similar to the latter case to selectively remove the alkyne from the vast majority of native phospholipids which are washed away.…”

Cobalt carbonyl complexes as probes for alkyne-tagged lipids

“…Phosphines are good ligands for alkyne-cobalt complexes, and phosphines on polystyrene ( 18 ), Novagel ( 20 ), and silica gel were examined as potential solid supports for ligation of the alkynyl lipid cobalt complexes. For small nonpolar alkynes, polystyrene-phosphine beads worked well.…”