Selective Formation of Mononuclear Palladium and Acetonitrile-Bridged Dinuclear Palladium Complexes Containing a Chiral Tridentate Ligand

There is a large interest in developing oxidative transformations catalyzed by palladium complexes that employ environmentally friendly and economical oxidizing reagents such as dioxygen. Recently, we have reported the isolation and characterization of various mononuclear PdIII and PdIV complexes supported by the tetradentate ligands N,N’-di-alkyl-butyl-2,11-diaza[3.3](2,6)pyridinophane (RN4, R = tBu, iPr, Me), and the aerobically-induced C-C and C-heteroatom bond formation reactivity was investigated in detail. Given that the steric and electronic properties of the multidentate ligands were shown to tune the stability and reactivity of the corresponding high-valent Pd complexes, herein we report the use of an asymmetric N4 ligand, N-mehtyl-N’-tosyl-2,11-diaza[3.3](2,6)pyridinophane (TsMeN4), in which one amine N atom contains a tosyl group. The N-Ts donor atom exhibits a markedly reduced donating ability, which led to the formation of transiently stable PdIII and PdIV complexes, and consequently the corresponding O2 oxidation reactivity and the subsequent C-C bond formation was improved significantly.

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Highly selective formation of unsaturated esters or cascade reactions to α,ω-diesters by the methoxycarbonylation of alkynes catalysed by palladium complexes of 1,2-bis(ditertbutylphosphinomethyl)benzene

Chemical Science ◽

10.1039/c0sc00276c ◽

2010 ◽

Vol 1 (6) ◽

pp. 723 ◽

Cited By ~ 63

Author(s):

A. Alberto Núñez Magro ◽

Lynzi-Marie Robb ◽

Peter J. Pogorzelec ◽

Alexandra M. Z. Slawin ◽

Graham R. Eastham ◽

...

Keyword(s):

Cascade Reactions ◽

Palladium Complexes ◽

Unsaturated Esters ◽

Selective Formation

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Improved Oxidative C-C Bond Formation Reactivity of High-Valent Pd Complexes Supported by a Pseudo-Tridentate Ligand

10.26434/chemrxiv.12480311 ◽

2020 ◽

Author(s):

Jason W. Schultz ◽

Nigam P. Rath ◽

Liviu M. Mirica

Keyword(s):

Bond Formation ◽

Palladium Complexes ◽

Tridentate Ligand ◽

Isolation And Characterization ◽

Oxidation Reactivity ◽

Tosyl Group ◽

Oxidative Transformations ◽

Pd Complexes ◽

High Valent ◽

The Stability

There is a large interest in developing oxidative transformations catalyzed by palladium complexes that employ environmentally friendly and economical oxidizing reagents such as dioxygen. Recently, we have reported the isolation and characterization of various mononuclear PdIII and PdIV complexes supported by the tetradentate ligands N,N’-di-alkyl-butyl-2,11-diaza[3.3](2,6)pyridinophane (RN4, R = tBu, iPr, Me), and the aerobically-induced C-C and C-heteroatom bond formation reactivity was investigated in detail. Given that the steric and electronic properties of the multidentate ligands were shown to tune the stability and reactivity of the corresponding high-valent Pd complexes, herein we report the use of an asymmetric N4 ligand, N-mehtyl-N’-tosyl-2,11-diaza[3.3](2,6)pyridinophane (TsMeN4), in which one amine N atom contains a tosyl group. The N-Ts donor atom exhibits a markedly reduced donating ability, which led to the formation of transiently stable PdIII and PdIV complexes, and consequently the corresponding O2 oxidation reactivity and the subsequent C-C bond formation was improved significantly.

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Metal-Metal Cooperative Bond Activation by Heterobimetallic Alkyl, Aryl, and Acetylide PtII/CuI Complexes

10.26434/chemrxiv.11742687 ◽

2020 ◽

Author(s):

Shubham Deolka ◽

Orestes Rivada Wheelaghan ◽

Sandra Aristizábal ◽

Robert Fayzullin ◽

Shrinwantu Pal ◽

...

Keyword(s):

Alkyl Group ◽

Bond Activation ◽

Bond Cleavage ◽

Terminal Alkyne ◽

Alkyl Aryl ◽

Metal Metal ◽

The Stability ◽

Selective Formation ◽

Organoplatinum Compounds

We report selective formation of heterobimetallic PtII/CuI complexes that demonstrate how facile bond activation processes can be achieved by altering reactivity of common organoplatinum compounds through their interaction with another metal center. The interaction of the Cu center with Pt center and with a Pt-bound alkyl group increases the stability of PtMe2 towards undesired rollover cyclometalation. The presence of the CuI center also enables facile transmetalation from electron-deficient tetraarylborate [B(ArF)4]- anion and mild C-H bond cleavage of a terminal alkyne, which was not observed in the absence of an electrophilic Cu center. The DFT study indicates that the role of Cu center acts as a binding site for alkyne substrate, while activating its terminal C-H bond.

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Gold Catalyzed Hydroamination of Propargylic Alcohols: Controlling Divergent Reaction Pathways to Access 1,3-Aminoalcohols, 3-Hydroxyketones or 3-Aminoketones

10.26434/chemrxiv.7160639 ◽

2018 ◽

Author(s):

Victor Laserna ◽

Tom Sheppard

Keyword(s):

Gold Catalysis ◽

Reaction Pathways ◽

High Yield ◽

Reaction Conditions ◽

Propargylic Alcohols ◽

Catalytic Quantity ◽

Selective Formation ◽

General Method

A versatile approach to the valorization of propargylic alcohols is reported, enabling controlled access to three different products from the same starting materials. Firstly, a general method for the hydroamination of propargylic alcohols with anilines is described using gold catalysis to give 3-hydroxy imines with complete regioselectivity. These 3-hydroxyimines can be reduced to give 1,3-aminoalcohols with high syn seletivity. Alternatively, by using a catalytic quantity of aniline, 3-hydroxyketones can be obtained in high yield directly from propargylic alcohols. Further manipulation of the reaction conditions enables the selective formation of 3-aminoketones via a rearrangement/hydroamination pathway.

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