Syntheses of Acyl Rhodium Porphyrins by Aldehydic Carbon−Hydrogen Bond Activation with Rh(III) Porphyrin Chloride and Methyl

Xu, Song; Chan, Kin Shing

doi:10.1021/om0507878

Cited by 38 publications

(37 citation statements)

References 30 publications

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“…However, only alkyl C–H bond activation (CHA) occurred to give 70% yield of 3a (eq 1 ). Compounds with similar structures have been reported in our previous work . When the stronger base of KOH was employed, the alkyl C–O bond-activation (COA) product was achieved ( 3b ) in 46% yield as well as alkyl C–H activation product ( 3a ) in 24% yield (eq 2 ).…”

Section: Resultssupporting

confidence: 63%

Alkyl Carbon–Oxygen Bond Cleavage of Aryl Alkyl Ethers by Iridium–Porphyrin and Rhodium–Porphyrin Complexes in Alkaline Media

Chen

Chan

2017

Organometallics

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Alkyl C–O bond cleavage in aryl alkyl ethers was achieved with Rh(ttp)Cl (1a; ttp = 5,10,15,20-tetrakis(p-tolyl)porphyrinato dianion) together with competitive alkyl C–H bond activation in alkaline media. In contrast, selective alkyl C–O bond cleavage occurred with the iridium–porphyrin Ir(ttp)(CO)Cl (1b)/KOH. Mechanistic investigations indicate the coexistence of MI(ttp)− and M2 II(ttp)2 (M = Rh, Ir) under basic conditions. With a weaker Rh(ttp)–Rh(ttp) bond, RhII(ttp)· metalloradical exists in an appreciable amount to cleave the alkyl C–H bond, competing with the alkyl C–O bond cleavage via RhI(ttp)−. In contrast, the more nucleophilic IrI(ttp)− cleaves the alkyl C–O bond exclusively.

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Section: Resultssupporting

confidence: 63%

Alkyl Carbon–Oxygen Bond Cleavage of Aryl Alkyl Ethers by Iridium–Porphyrin and Rhodium–Porphyrin Complexes in Alkaline Media

Chen

Chan

2017

Organometallics

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“…Aza‐BODIPY‐a , aza‐BODIPY‐b , and rhodium(III) tetrakis‐4‐tolylporphyrin chloride ([Rh III (ttp)Cl]) were prepared according to literature procedures. The Rh III (ttp)‐aza‐BODIPY conjugates were linked either through the para position of the phenyl substituent of the aza‐BODIPY fluorophore ( 1 a ) or through one of the meta positions ( 1 b ).…”

Section: Resultscontrasting

confidence: 99%

Rational Design of Emissive NIR‐Absorbing Chromophores: Rh^III Porphyrin‐Aza‐BODIPY Conjugates with Orthogonal Metal–Carbon Bonds

Zhou

Gai

Zhou

et al. 2016

Chemistry A European J

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The facile synthesis of Group 9 Rh(III) porphyrin-aza-BODIPY conjugates that are linked through an orthogonal Rh-C(aryl) bond is reported. The conjugates combine the advantages of the near-IR (NIR) absorption and intense fluorescence of aza-BODIPY dyes with the long-lived triplet states of transition metal rhodium porphyrins. Only one emission peak centered at about 720 nm is observed, irrespective of the excitation wavelength, demonstrating that the conjugates act as unique molecules rather than as dyads. The generation of a locally excited (LE) state with intramolecular charge-transfer (ICT) character has been demonstrated by solvatochromic effects in the photophysical properties, singlet oxygen quantum yields in polar solvents, and by the results of density functional theory (DFT) calculations. In nonpolar solvents, the Rh(III) conjugates exhibit strong aza-BODIPY-centered fluorescence at around 720 nm (ΦF =17-34 %), and negligible singlet oxygen generation. In polar solvents, enhancements of the singlet-oxygen quantum yield (ΦΔ =19-27 %, λex =690 nm) have been observed. Nanosecond pulsed time-resolved absorption spectroscopy confirms that relatively long-lived triplet excited states are formed. The synthetic methodology outlined herein provides a useful strategy for the assembly of functional materials that are highly desirable for a wide range of applications in material science and biomedical fields.

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“…Clearly, the potential of azuliporphyrins in this field provides numerous opportunities for further research. Rhodium(III) porphyrins are well-known and have demonstrated efficient and selective carbon–hydrogen bond activation. − In addition, rhodium(III) N-confused porphyrins have been prepared, and related organometallic complexes derived from expanded porphyrins such as hexaphyrins(1.1.1.1.1.1) have been described . Rh(IV) complexes of N-confused porphyrins also effectively promote stereoselective cyclopropanation reactions with alkenes .…”

Section: Introductionmentioning

confidence: 99%

Rhodium(III) Azuliporphyrins

2015

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The organometallic chemistry of azuliporphyrins has been extended to the first syntheses of rhodium(III) derivatives. Reaction of [Rh(CO) 2 Cl] 2 with an azuliporphyrin in refluxing xylenes gave rhodium(III) azuliporphyrins in 62− 67% yield. These derivatives incorporate solvent molecules as axial ligands and thereby introduce two carbon−rhodium bonds in a three-component reaction. The methylbenzyl ligands that are derived from xylenes overlie the π system of the porphyrinoid macrocycle, and proton NMR spectra show that these units are strongly shielded. The o-, m-, and p-xylene-derived complexes were characterized by X-ray crystallography, and this confirmed the presence of the central rhodium atom and the axial benzylic ligands. Additionally, when the azuliporphyrin was reacted with [Rh(CO) 2 Cl] 2 in refluxing acetonitrile and then treated with acetone and basic alumina, a rhodium(III) azuliporphyrin with an acetone-derived axial ligand was generated. These results demonstrate that azuliporphyrins are superior organometallic ligands and therefore merit further investigation.

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Syntheses of Acyl Rhodium Porphyrins by Aldehydic Carbon−Hydrogen Bond Activation with Rh(III) Porphyrin Chloride and Methyl

Cited by 38 publications

References 30 publications

Alkyl Carbon–Oxygen Bond Cleavage of Aryl Alkyl Ethers by Iridium–Porphyrin and Rhodium–Porphyrin Complexes in Alkaline Media

Alkyl Carbon–Oxygen Bond Cleavage of Aryl Alkyl Ethers by Iridium–Porphyrin and Rhodium–Porphyrin Complexes in Alkaline Media

Rational Design of Emissive NIR‐Absorbing Chromophores: Rh^III Porphyrin‐Aza‐BODIPY Conjugates with Orthogonal Metal–Carbon Bonds

Rhodium(III) Azuliporphyrins

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Syntheses of Acyl Rhodium Porphyrins by Aldehydic Carbon−Hydrogen Bond Activation with Rh(III) Porphyrin Chloride and Methyl

Cited by 38 publications

References 30 publications

Alkyl Carbon–Oxygen Bond Cleavage of Aryl Alkyl Ethers by Iridium–Porphyrin and Rhodium–Porphyrin Complexes in Alkaline Media

Alkyl Carbon–Oxygen Bond Cleavage of Aryl Alkyl Ethers by Iridium–Porphyrin and Rhodium–Porphyrin Complexes in Alkaline Media

Rational Design of Emissive NIR‐Absorbing Chromophores: RhIII Porphyrin‐Aza‐BODIPY Conjugates with Orthogonal Metal–Carbon Bonds

Rhodium(III) Azuliporphyrins

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Product

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About

Rational Design of Emissive NIR‐Absorbing Chromophores: Rh^III Porphyrin‐Aza‐BODIPY Conjugates with Orthogonal Metal–Carbon Bonds