Synthetic sudies related to myoglobin: syntheses of bridged porphyrin systems

Abstract

Sunzi~znry Routes are developed for synthesis of porphyrins carrying functionalised bridges over tlle rnacrocycle ; the FeII coriiplescs of these products are of interest in relation t o niyoglobin and liaemoglobin.

Synthese und Struktur porphinoider Nickel‐Komplexe mit axial orientierten Seitenketten

“…The two methoxy groups in 3 are cis-oriented. The syntheses and spectroscopic properties of [ 1,11 -diethoxy-10H-HDP (2-)]nickel (5), [l, 11-dineopentyloxy-I0 H-HDP (2-)]nickel (6) as well as the bridged complexes [ 1,ll-pentamethylenedioxy-10 H-HDP (2-)]nickel (4) and [ I , 1 1 -(E)-2,3-dimethyl-2-butenylenedioxy)-l0 H-HDP (2-)]nickel (7) are described. Reaction of 1 with bromide ions or 4-methylpyridine leads to the formation of the corresponding hexacoordinated, paramagnetic complexes dibromo[6 H-HDPInickel (11) (8) and bis (4-methylpyridine) [6 H-HDPInickel-bis (tt:trafluoroborate) (9).…”

“…Beispiele dazu sind die Coenzym-B12-Modelle von Retey [2] und Robinson [3], das Myoglobin-Model1 von Battersby et al [4] und Studien am Oxen-Komplex des Cytochrom I)…”

“…Die in Figur I spiegelbildlich zum Spektrum dargestellte Spur der Computersimulierung eines ABXY-Systems mit den aufgefuhrten Werten ist im XY-Teil (HI, H2) gut iibereinstimmend7). Die Kopplungskonstanten J ( l , 2 ) = 11 und J (3,4) periplanar und g = gauche (synclinal) mit gleichem Torsionssinn bedeuteng). In dieser Konformation nehmen die je zwei diastereotopen Protonen der beiden CH20-Gruppen extrem unterschiedliche raumliche Positionen ein; die nach innen gegen das Zentralatom gerichteten Protonenlo) sind im 'H-NMR.-Spektrum aussergewohnlich stark abgeschirmt (5,87 ppm), wahrend die nach aussen weisenden Protonen bei normaler Lage (336 ppm) absorbieren").…”

Radical-induced pseudocontact shifts

“…In order to obtain "high resolution" NMR spectra, it has become customary to subject multilamellar dispersions to pro-0002-7863/78/1500-1296$01.00/0 longed ultrasonic irradiation.5 This process, which results in particles of reduced size with reduced reorientational correlation times, does indeed improve the resolution of the NMR spectra; however, its exact physical and chemical consequences are a subject of much debate. 6 We report an approach which avoids sonication.…”

Synthesis and characterization of durene-capped porphyrins and the crystal structure of a hemin derivative

“…In a modification of this method, the protective structures are linked to the aromatic aldehydes at their ortho positions via ester or ether functions, prior to the coupling with pyrrole (7, 9, 10). The most widely used approach to the synthesis of hindered porphyrins has been to condense, via ester or amide linkages, a diagonally P-substituted preformed porphyrin with a terminally bifunctional molecule carrying appropriate functional groups (8,11,(13)(14)(15).…”