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

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.

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

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.

scholarly journals Metal–metal cooperative bond activation by heterobimetallic alkyl, aryl, and acetylide PtII/CuI complexes

2020 ◽  
Vol 11 (21) ◽  
pp. 5494-5502 ◽  
Author(s):  
Shubham Deolka ◽  
Orestes Rivada-Wheelaghan ◽  
Sandra L. Aristizábal ◽  
Robert R. Fayzullin ◽  
Shrinwantu Pal ◽  
...  
Keyword(s):  
Bond Activation ◽  
Metal Center ◽  
Alkyl Aryl ◽  
Metal Metal ◽  
Selective Formation ◽  
Organoplatinum Compounds

The selective formation of heterobimetallic PtII/CuI complexes demonstrates how facile bond activation processes can be achieved by altering the reactivity of common organoplatinum compounds through their interaction with another metal center.

On the role of the surface oxygen species during A–H (A = C, N, O) bond activation: a density functional theory study

2015 ◽  
Vol 51 (13) ◽  
pp. 2621-2624 ◽  
Author(s):  
Jong Suk Yoo ◽  
Tuhin S. Khan ◽  
Frank Abild-Pedersen ◽  
Jens K. Nørskov ◽  
Felix Studt
Keyword(s):  
Density Functional ◽  
Bond Activation ◽  
Bond Cleavage ◽  
Oxygen Species ◽  
Final States ◽  
Surface Oxygen ◽  
Density Functional Theory Study ◽  
Reaction Energy ◽  
Functional Theory

During A–H (A = C, N, O) bond cleavage on O* or OH* pre-covered (111) surfaces, the oxygen species play the role of modifying the reaction energy by changing the species involved in the initial and final states of the reaction.

scholarly journals Consecutive C–F bond activation and C–F bond formation of heteroaromatics at rhodium: the peculiar role of FSi(OEt)3

2015 ◽  
Vol 6 (7) ◽  
pp. 4255-4260 ◽  
Author(s):  
A. L. Raza ◽  
T. Braun
Keyword(s):  
Bond Activation ◽  
Bond Cleavage ◽  
Bond Formation ◽  
Cleavage Reaction ◽  
Bond Cleavage Reaction ◽  
Consecutive Reactions ◽  
Silyl Complex

C–F activation reactions for a silyl complex gave fluorosilane and Rh pyridyl complexes. In consecutive reactions, the fluorosilane can act as a fluoride source and a regeneration of the C–F bond occurs by Si–F bond cleavage. This sets back the C–F bond cleavage reaction with consequences for the overall chemoselectivity of the activation reactions.

Acetic Acid-Promoted Rhodium(III)-Catalyzed Hydroarylation of Terminal Alkynes

Synlett ◽  
2019 ◽  
Vol 30 (08) ◽  
pp. 932-938 ◽  
Author(s):  
Chang-Lin Duan ◽  
Xing-Yu Liu ◽  
Yun-Xuan Tan ◽  
Rui Ding ◽  
Shiping Yang ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Functional Group ◽  
Bond Activation ◽  
Side Reactions ◽  
Terminal Alkynes ◽  
Terminal Alkyne ◽  
Mechanistic Studies ◽  
Mild Conditions ◽  
Reaction Proceeds

Rhodium(III)-catalyzed hydroarylation of terminal alkynes has not previously been achieved because of the inevitable oligomerization and other side reactions. Here, we report a novel Cp*Rh(III)-catalyzed hydroarylation of terminal alkynes in acetic acid as solvent to facilitate the C–H bond activation and subsequent transformations. This reaction proceeds under mild conditions, providing an effective approach to the synthesis of alkenylated heterocycles in high to excellent yields (31–99%) with a broad substrate scope (37 examples) and good functional-group compatibility. In this transformation, the loading of the alkyne can be reduced to 1.2 equivalents, which indicates the significant role of HOAc in lowering the reaction temperature and suppressing the oligomerization of the terminal alkyne. Preliminary mechanistic studies are also presented.

A Statistical Study of Process Variables to Optimize a High Speed Curtain Coater: Part I

TAPPI Journal ◽  
2009 ◽  
Vol 8 (1) ◽  
pp. 20-26 ◽  
Author(s):  
PEEYUSH TRIPATHI ◽  
MARGARET JOYCE ◽  
PAUL D. FLEMING ◽  
MASAHIRO SUGIHARA
Keyword(s):  
Boundary Layer ◽  
Experimental Design ◽  
High Speed ◽  
Statistical Study ◽  
Process Variables ◽  
High Speeds ◽  
The Stability ◽  
Air Removal ◽  
Removal System

Using an experimental design approach, researchers altered process parameters and material prop-erties to stabilize the curtain of a pilot curtain coater at high speeds. Part I of this paper identifies the four significant variables that influence curtain stability. The boundary layer air removal system was critical to the stability of the curtain and base sheet roughness was found to be very important. A shear thinning coating rheology and higher curtain heights improved the curtain stability at high speeds. The sizing of the base sheet affected coverage and cur-tain stability because of its effect on base sheet wettability. The role of surfactant was inconclusive. Part II of this paper will report on further optimization of curtain stability with these four variables using a D-optimal partial-facto-rial design.

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