Reactivity and kinetic–mechanistic studies of regioselective reactions of rhodium porphyrins with unactivated olefins in water that form β-hydroxyalkyl complexes and conversion to ketones and epoxides

Abstract

This article reports on the selective oxidation of unactivated alkenes to ketones and epoxides through the intermediacy of beta-hydroxyalkyl rhodium porphyrin complexes which are formed by reactions of terminal alkenes with tetra(p-sulfonatophenyl)porphyrin rhodium(III) complex. The beta-hydroxyalkyl rhodium porphyrin complexes in water undergo beta-C-H elimination to produce ketones in aqueous pH 9.0 solutions and O-H deprotonation in KOH/DMSO solutions resulting in the rapid and quantitative intramolecular nucleophilic displacement to form 1,2-epoxyalkanes.

A Facile Palladium‐Mediated Contraction of Benzene to Cyclopentadiene: Transformations of Palladium(II) p‐Benziporphyrin

“…Significantly, in spite of the intensive exploration of metallocarbaporphyrinoids, 4 ( Figure 5) and 5 are the very first representatives of 21-carbaporphyrin complexes. [13,15,[23][24][25] A feasible mechanism of contraction consistent with formation of 3, 4, and 5 is shown in Scheme 3 and comprise the following major steps: 1) addition of palladium(II) and a hydroxide ion to the C(21)-C(22) double bond, [26] 2) b elimination, [27] and 3) competing contractions by 1,2-hydride shift or cheletropic extrusion of carbon oxide. The contraction is accompanied by a relief of strain energy of the embedded conjugated 1,3-cyclohexadiene ring and finally by the formation of a new aromatic porphyrinoid system.…”

1H NMR Spectroscopy as an Effective Method for Predicting Molecular Weight of Polyaminoamine Dendrimers and Their Derivatives

“…Chemical shifts for typical protons in PAMAM dendrimer generations were noted according to many previous reports [10,14,15,[18][19][20]24] and are given here: 1 …”

“…[9] In comparison with gas chromatography (GC), gel permeation chromatography (GPC). and mass spectroscopy techniques, 1 H-NMR has considerable advantages for use as a simple measurement method that gives exact results and can be used for a wide variety of molecules (small organic molecules, complexes, polymers, and supramolecules). [6,8] For determination of molecular weight and polymerization degree using 1 H NMR, notably, the calculated values are in agreement with the results from other mentioned methods.…”

“…In addition, it has been used as a qualitative and quantitative method for evaluating reaction progress in organic synthesis, [1] molecular weight of polymers in polymerization or condensation, [2][3][4][5] degree of functionalization, [6] composition of organic molecules, [7,8] and metabolization in pharmacological assays. [9] In comparison with gas chromatography (GC), gel permeation chromatography (GPC).…”

“…The crude product was dialyzed (MWCO 3,500-5,000 Da dialysis bags) with MeOH for 48 h and dried in vacuo to obtain the G3.0-C6 product. The structure and properties of the product were determined by 1 …”