Nitrito–nitro linkage isomerisation of the penta-amminecobalt(<scp>III</scp>) complex in liquid ammonia

Balt, S.; Kuipers, Henricus J. A. M.; RENKEMA, W. E.

doi:10.1039/dt9830001739

Cited by 8 publications

(2 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A solution of HOBt (1.05 g, 6.84 mmol) in DMF (3.0 mL) was added, and the mixture was stirred for 15 min at 0 "C. DIC (1.08 mL, 6.84 mmol) was then added, and the reaction was stirred at 0 "C while monitoring the progress of the reaction by HPLC' at 254 nm with 40% Synthesis of Co(NH3)4-complexes trans-(CNNH3)4(SO3)OH]. This complex was prepared following the method described in the literature (56). (NH&(SO.7)4-AMB/ (5).…”

Section: Cis-[cq'en)d4-amb-obt)o-aa-boc](tfmsa)2 (4) Thementioning

confidence: 99%

Solid‐phase synthesis of protected peptides using new cobalt(III) ammine linkers^†

Arbo¹,

Isied²

1993

International Journal of Peptide and Protein Research

View full text Add to dashboard Cite

Cobalt(lI1) ammine complexes of the type cis-[ C~L J (~-A M B ) O -A A -B~C ] ( C F~S O~) * ,where L4 = bisethylenediamine (en)z or tetraammine ( N H~) J , and 4-AMB = 4-(aminomethy1)benzoic acid, have been synthesized and used as linkers to polystyrene resins for solid-phase synthesis of protected peptides. Boc/t-Buprotected [ Leus]enkephaEn was assembled on the two different Co(II1) resins, and then cleaved from the resins by reduction of the Co(II1) center in 93-960; yield. HPLC-purified protected [ Leu5]enkephalin was obtained in 67-69;, overall yield and characterized by amino acid analysis and 'H NMR. Stepwise synthesis on the Co(en)l-resin was also used in the assembly of Boc-Asp(0cHex)-Arg(Mts)-Gly-Asp(0cHex)-Ala-Pro-Lys(2CI-Z)-Gly-OH, a sequence from collagen z1 Type 1. The protected peptide was cleaved from the Co(1II) resin in 745: yield, and the HPLC-purified nonapeptide was characterized by amino acid analysis, lH NMR and liquid secondary-ion mass spectrometry (LSIMS). New routes are described for the synthesis of isomerically pure Co(II1) anchor complexes. The Co(II1) resins were found to be compatible with both the tert-butyloxycarbonyl (Boc) and the 9-fluorenylmethoxycarbonyl (Fmoc) N"-protecting group strategies used in solid-phase peptide synthesis. 0 Munksgaard 1993. K e j nwdst Co(en)z-anchor complex; Co(NHi)J-anchor complex: Co(lI1) handle; [ Leus]enkephalin; protected peptides; solid-phase peptide sqnthesis

show abstract

Section: Cis-[cq'en)d4-amb-obt)o-aa-boc](tfmsa)2 (4) Thementioning

confidence: 99%

Solid‐phase synthesis of protected peptides using new cobalt(III) ammine linkers^†

Arbo¹,

Isied²

1993

International Journal of Peptide and Protein Research

View full text Add to dashboard Cite

show abstract

“…Linkage isomerization has been studied for a variety of transition-metal complexes of heteroatom compounds, [25] which includes NO, [26] NO 2 , [27] SO 2 , [28] Me 2 SO, [28a] SCN, [28b] amides, [29] and enolates.…”

mentioning

confidence: 99%

Switchable C‐ and N‐Bound Isomers of Transition‐Metal Cyanocarbanions: Synthesis and Interconversions of Cyclopentadienyl Ruthenium Complexes of Phenylsulfonylacetonitrile Anions

Tannna¹,

Kamuro²,

Hieda³

et al. 2008

Chemistry A European J

View full text Add to dashboard Cite

The synthesis, structure, and dynamic behavior of bistable C- and N-bound isomers of transition-metal cyanocarbanions are described. A series of C-bound cyclopentadienyl (Cp) ruthenium phosphane complexes, [Ru{CH(CN)SO2Ph}(Cp)L1L2] (3), and their N-bound isomers, [Ru+(Cp)(NCCH(-)SO2Ph)L1L2] (4), were prepared by treating [RuCl(Cp)(PR3)2] with the sodium salt of phenylsulfonylacetonitrile and performing ligand-exchange reactions with the resulting compounds. Structural characterization by X-ray diffraction indicates that the cyanocarbanion moiety of 3 has an alpha-metalated structure, whereas that of 4 has a zwitterionic, end-on structure. Heating these complexes in aprotic solvents gives rise to irreversible linkage isomerization between C- and N-bound isomers, in which the relative thermal stabilities vary greatly depending on the steric and electronic nature of the ligands. Mechanistic studies of N-to-C isomerization revealed that the reaction proceeds irreversibly in a unimolecular manner without the formation of coordinatively unsaturated species. A metal-sliding process, which occurs over the -C-C triple chemical bond N pi-conjugated surface of the cyanocarbanion moiety, was suggested by results from kinetic studies and density functional theory (DFT) calculations. C-to-N isomerizations proceed by the above-mentioned intramolecular process, with a temperature-dependent contribution from the formation and cleavage of mu2-C,N coordination dimers [{Ru{CH(CN)SO2Ph}(Cp)(PPh3)}2] (15 and 16).

show abstract

ChemInform Abstract: NITRITO‐NITRO LINKAGE ISOMERIZATION OF THE PENTAAMMINECOBALT(III) COMPLEX IN LIQUID AMMONIA

Balt¹,

Kuipers²,

RENKEMA³

1983

Chemischer Informationsdienst

View full text Add to dashboard Cite

show abstract

Nitrito–nitro linkage isomerisation of the penta-amminecobalt(III) complex in liquid ammonia

Cited by 8 publications

References 1 publication

Solid‐phase synthesis of protected peptides using new cobalt(III) ammine linkers^†

Solid‐phase synthesis of protected peptides using new cobalt(III) ammine linkers^†

Switchable C‐ and N‐Bound Isomers of Transition‐Metal Cyanocarbanions: Synthesis and Interconversions of Cyclopentadienyl Ruthenium Complexes of Phenylsulfonylacetonitrile Anions

ChemInform Abstract: NITRITO‐NITRO LINKAGE ISOMERIZATION OF THE PENTAAMMINECOBALT(III) COMPLEX IN LIQUID AMMONIA

Contact Info

Product

Resources

About

Nitrito–nitro linkage isomerisation of the penta-amminecobalt(III) complex in liquid ammonia

Cited by 8 publications

References 1 publication

Solid‐phase synthesis of protected peptides using new cobalt(III) ammine linkers†

Solid‐phase synthesis of protected peptides using new cobalt(III) ammine linkers†

Switchable C‐ and N‐Bound Isomers of Transition‐Metal Cyanocarbanions: Synthesis and Interconversions of Cyclopentadienyl Ruthenium Complexes of Phenylsulfonylacetonitrile Anions

ChemInform Abstract: NITRITO‐NITRO LINKAGE ISOMERIZATION OF THE PENTAAMMINECOBALT(III) COMPLEX IN LIQUID AMMONIA

Contact Info

Product

Resources

About

Solid‐phase synthesis of protected peptides using new cobalt(III) ammine linkers^†

Solid‐phase synthesis of protected peptides using new cobalt(III) ammine linkers^†