ChemInform Abstract: Site-Selective Mono-Oxidative Addition of Active Zinc into Carbon-Bromine Bond of Dibrominated-Thiophenes: Preparation of Thienylzinc Reagents and Their Applications.

Heterobimetallic bis-NHC complexes have been obtained by the site-selective metallation of 8-iodotheophylline/imidazolium bis-NHC precursors using a combination of deprotonation-metallation and oxidative addition reactions.

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Site-selective mono-oxidative addition of active zinc into carbon–bromine bond of dibrominated-thiophenes: preparation of thienylzinc reagents and their applications

Tetrahedron Letters ◽

10.1016/j.tetlet.2012.12.024 ◽

2013 ◽

Vol 54 (8) ◽

pp. 960-964 ◽

Cited By ~ 7

Author(s):

Hye-Soo Jung ◽

Hyun-Hee Cho ◽

Seung-Hoi Kim

Keyword(s):

Oxidative Addition ◽

Site Selective

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Electrostatically-directed Pd-catalysis in combination with C–H activation: site-selective coupling of remote chlorides with fluoroarenes and fluoroheteroarenes

Chemical Science ◽

10.1039/d0sc00105h ◽

2020 ◽

Vol 11 (11) ◽

pp. 3022-3027 ◽

Cited By ~ 5

Author(s):

William A. Golding ◽

Robert J. Phipps

Keyword(s):

Oxidative Addition ◽

Site Selective ◽

Activation Site

Electrostatically-directed oxidative addition is compatible with a subsequent C–H activation step, enabling site-selective coupling of remote chlorides with fluoroarenes and fluoroheteroarenes.

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Some Problems in the Oxidative Addition and Binding of an Ethylene to a Transition Metal Center.

Organometallics ◽

10.1021/om00147a600 ◽

1987 ◽

Vol 6 (4) ◽

pp. 902-902

Author(s):

Jerome Silestre ◽

Maria Calhorda ◽

Roald Hoffman ◽

Page Stoutland ◽

Robert Bergman

Keyword(s):

Transition Metal ◽

Oxidative Addition ◽

Metal Center

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Chemical and Electrochemical Heteroepitaxial Growth of Chalcogenide Semiconductors from Solutions

MRS Proceedings ◽

10.1557/proc-451-223 ◽

1996 ◽

Vol 451 ◽

Cited By ~ 4

Author(s):

D. Lincot ◽

M. J. Furlong ◽

M. Froment ◽

R. Cortes ◽

M. C. Bernard

Keyword(s):

Heteroepitaxial Growth ◽

X Ray Diffraction ◽

Basic Principles ◽

Lattice Match ◽

X Ray ◽

Chalcogenide Semiconductors ◽

Influence Of Temperature On ◽

Deposition Processes ◽

A Site ◽

Site Selective

ABSTRACTChalcogenide semiconductors have been deposited epitaxially from aqueous solutions either chemically or electrochemically at growth rates of up to 0.7 μmhr−1. After recalling the basic principles of these deposition processes, results are presented concerning chemically deposited CdS on InP, GaP and CuInSe2 substrates, electrodeposited CdTe on InP, and CdSAnP heterostructures. Characterisation of these structures by RHEED, TEM, HRTEM, and glazing angle X ray diffraction allows to analyse the effects of substrate orientation, polarity, lattice match plus the influence of temperature on epitaxial growth. These results are discussed in terms of self organisation and a site selective growth mechanisms due to the free enegy of formation of each compound.

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para-Selective Cyanation of Arenes by H-Bonded Template

10.26434/chemrxiv.11448690.v1 ◽

2019 ◽

Author(s):

Sandeep Pimparkar ◽

Trisha Bhattacharya ◽

Arun Maji ◽

Argha Saha ◽

Ramasamy Jayarajan ◽

...

Keyword(s):

Selective Functionalization ◽

Directing Group ◽

Product Utility ◽

Site Selective

The significance of site selective functionalization stands upon the superior selectivity, easy synthesis and diverse product utility. In this work we demonstrate the para-selective introduction of versatile nitrile moiety, enabled by detachable and reusable H-bonded auxiliary. The methodology holds its efficiency irrespective of substrate electronic bias. The conspicuous shift in the step energetics was probed by both experimental and computational mechanistic tools heralds the inception of para-deuteration. The synthetic impact of the methodology was highlighted with reusability of directing group and post synthetic modifications

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para-Selective Cyanation of Arenes by H-Bonded Template

10.26434/chemrxiv.11448690 ◽

2019 ◽

Author(s):

Sandeep Pimparkar ◽

Trisha Bhattacharya ◽

Arun Maji ◽

Argha Saha ◽

Ramasamy Jayarajan ◽

...

Keyword(s):

Selective Functionalization ◽

Directing Group ◽

Product Utility ◽

Site Selective

The significance of site selective functionalization stands upon the superior selectivity, easy synthesis and diverse product utility. In this work we demonstrate the para-selective introduction of versatile nitrile moiety, enabled by detachable and reusable H-bonded auxiliary. The methodology holds its efficiency irrespective of substrate electronic bias. The conspicuous shift in the step energetics was probed by both experimental and computational mechanistic tools heralds the inception of para-deuteration. The synthetic impact of the methodology was highlighted with reusability of directing group and post synthetic modifications

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Reversible Oxidative-Addition and Reductive-Elimination of Thiophene from a Titanium Complex and Its Thermally-Induced Hydrodesulfurization Chemistry

10.26434/chemrxiv.10321946.v1 ◽

2019 ◽

Author(s):

Alejandra Gomez-Torres ◽

J. Rolando Aguilar-Calderón ◽

Carlos Saucedo ◽

Aldo Jordan ◽

Alejandro J. Metta-Magaña ◽

...

Keyword(s):

Dft Calculations ◽

Ring Opening ◽

Thiophene Ring ◽

Oxidative Addition ◽

Reductive Elimination ◽

Thermally Induced ◽

Titanium Complex

The masked Ti(II) synthon (Ketguan)(η6-ImDippN)Ti (1) oxidatively adds across thiophene to give ring-opened (Ketguan)(ImDippN)Ti[κ2-S(CH)3CH] (2). Complex 2 is photosensitive, and upon exposure to light, reductively eliminates thiophene to regenerate 1 – a rare example of early-metal mediated oxidative-addition/reductive-elimination chemistry. DFT calculations indicate strong titanium π-backdonation to the thiophene π*-orbitals leads to the observed thiophene ring opening across titanium, while a proposed photoinduced LMCT promotes the reverse thiophene elimination from 2. Finally, pressurizing solutions of 2 with H2 (150 psi) at 80 °C leads to the hydrodesulfurization of thiophene to give the Ti(IV) sulfide (Ketguan)(ImDippN)Ti(S) (3) and butane.

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Cobalt/Lewis Acid Catalysis for Hydrocarbofunctionalization of Alkynes via Cooperative C–H Activation

10.26434/chemrxiv.11760519.v1 ◽

2020 ◽

Author(s):

Chang-Sheng Wang ◽

Sabrina Monaco ◽

Anh Ngoc Thai ◽

Md. Shafiqur Rahman ◽

Chen Wang ◽

...

Keyword(s):

Catalytic System ◽

Lewis Acid ◽

Hydrogen Transfer ◽

Acid Catalysis ◽

Rate Limiting Step ◽

Site Selectivity ◽

Set Up ◽

Site Selective ◽

First Time ◽

Rate Limiting

A catalytic system comprised of a cobalt-diphosphine complex and a Lewis acid (LA) such as AlMe3 has been found to promote hydrocarbofunctionalization reactions of alkynes with Lewis basic and electron-deficient substrates such as formamides, pyridones, pyridines, and azole derivatives through site-selective C-H activation. Compared with known Ni/LA catalytic system for analogous transformations, the present catalytic system not only feature convenient set up using inexpensive and bench-stable precatalyst and ligand such as Co(acac)3 and 1,3-bis(diphenylphosphino)propane (dppp), but also display distinct site-selectivity toward C-H activation of pyridone and pyridine derivatives. In particular, a completely C4-selective alkenylation of pyridine has been achieved for the first time. Mechanistic stidies including DFT calculations on the Co/Al-catalyzed addition of formamide to alkyne have suggested that the reaction involves cleavage of the carbamoyl C-H bond as the rate-limiting step, which proceeds through a ligand-to-ligand hydrogen transfer (LLHT) mechanism leading to an alkyl(carbamoyl)cobalt intermediate.

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