Selective formation of heterocyclic trans-cycloalkenes by alkyne addition to a biphenylene-based phosphane/borane frustrated Lewis pair

2018 ◽  
Vol 54 (49) ◽  
pp. 6344-6347 ◽  
Author(s):  
Jun Li ◽  
Constantin G. Daniliuc ◽  
Gerald Kehr ◽  
Gerhard Erker
Keyword(s):  
Frustrated Lewis Pair ◽  
Alkyne Addition ◽  
Selective Formation

A biphenylene based P/B FLP reacts with 1-alkynes through trans-1,2-addition to give heterocyclic E-cycloalkene products.

Reaction of an Al/P-based frustrated Lewis pair with benzophenone: formation of adducts and aluminium alcoholates via β-hydride elimination

2016 ◽  
Vol 71 (10) ◽  
pp. 1043-1050 ◽  
Author(s):  
Werner Uhl ◽  
Philipp Wegener ◽  
Marcus Layh ◽  
Alexander Hepp ◽  
Ernst-Ulrich Würthwein
Keyword(s):  
Quantum Chemical ◽  
Aluminum Atom ◽  
Carbonyl Carbon Atom ◽  
Carbonyl Carbon ◽  
Hydride Shift ◽  
Frustrated Lewis Pair ◽  
Donor Acceptor ◽  
Hydride Elimination ◽  
Selective Formation ◽  
Quantum Chemical Dft Calculations

AbstractTreatment of the Al/P-based frustrated Lewis pair (FLP) Mes2P–C(AltBu2)=C(H)-Ph (1) with benzophenone afforded the simple 1:1 adduct (4) with a O=CPh2 molecule coordinated to the aluminum atom by an Al←O donor-acceptor bond. Steric repulsion may prevent an interaction between the electrophilic carbonyl carbon atom and the Lewis-basic phosphorus atom. 4 is unstable in solution at room temperature, the coordination to aluminium increases the polarisation of the carbonyl group and favours its reduction. As suggested by quantum chemical calculations, a C–H bond of a tBu group approaches the electrophilic center and facilitates β-hydride elimination with the release of isobutene and the formation of an Al–OCHPh2 ligation. An intact O=CPh2 molecule completes the coordination sphere of the metal atom (5). The second tBu group at aluminium reacts similarly by the selective formation of an Al(OCHPh2)2 moiety (6). The thermodynamics of adduct formation and the mechanism of the hydride shift have been evaluated by quantum chemical DFT calculations.

Facile 1,1-Carboboration Reaction of a Diarylphosphino-substituted Conjugated Diyne with Tris(pentafluorophenyl)borane

2013 ◽  
Vol 68 (5-6) ◽  
pp. 666-674 ◽  
Author(s):  
Philipp Feldhaus ◽  
Gerald Kehr ◽  
Roland Fröhlich ◽  
Constantin G. Daniliuc ◽  
Gerhard Erker
Keyword(s):  
Crystal Structure ◽  
Carbon Atom ◽  
Substitution Reaction ◽  
Nucleophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
X Ray ◽  
Frustrated Lewis Pair ◽  
Selective Formation

Bis(dimesitylphosphanyl)butadiyne (14) reacts with B(C6F5)3 by a 1,1-carboboration sequence. The selective attack at a single phosphanyl-alkyne moiety is observed. First a phosphirenium-borate zwitterion 15 is formed at r. t. Thermolysis (80 °C) results in the E-selective formation of the 1,1- carboboration product, the frustrated Lewis pair (FLP) E-16, which upon heating to 160 °C eventually undergoes isomerization followed by an internal nucleophilic aromatic substitution reaction to give the product 17 featuring a -B(F)(C6F5)2 substituent at the five-membered P-heterocycle. Finally, the FLP E-16 was reacted with n-butylisocyanide to yield the five-membered heterocyclic product 18, formed by P,B addition to the isonitrile carbon atom. Compounds 14, 15, 17, and 18 were characterized by X-ray crystal structure analyses

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.

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

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.<br>

scholarly journals Hydrogenation of secondary amides using phosphane oxide and frustrated Lewis pair catalysis

2021 ◽  
Author(s):  
Laura Köring ◽  
Nikolai A. Sitte ◽  
Markus Bursch ◽  
Stefan Grimme ◽  
Jan Henry Hakan Paradies
Keyword(s):  
Frustrated Lewis Pair ◽  
Secondary Amides

Selective Formation of a Supramolecular Coordination Complex in the Nanometre Scale with a Ferrocene-based Phospholane Ligand

2021 ◽  
Author(s):  
Reinhard Hoy ◽  
Toni Grell ◽  
Peter Lönnecke ◽  
Evamarie Hey-Hawkins
Keyword(s):  
Coordination Complex ◽  
Supramolecular Coordination ◽  
Selective Formation

A straightforward synthesis of the tetradentate phospholane ligand 1 is reported. The 2:1 [M:L] reaction of 1 with [AuCl(tht)] (tht = tetrahydrothiophen) resulted in a 4:2 [M:L] supramolecular coordination complex...

Bis(perchlorocatecholato)silane and Heteroleptic Bidonors: Hidden Frustrated Lewis Pairs by Ring Strain

2021 ◽  
Author(s):  
Deborah Hartmann ◽  
Sven Braner ◽  
Lutz Greb
Keyword(s):  
Ammonia Borane ◽  
Frustrated Lewis Pairs ◽  
Ring Strain ◽  
Frustrated Lewis Pair ◽  
Lewis Pairs

Bis(perchlorocatecholato)silane and bidentate N,N- or N,P-heteroleptic donors form hexacoordinated complexes. Depending on the ring strain and hemilability in the adducts, Frustrated Lewis pair reactivity with aldehydes and catalytic ammonia borane...

scholarly journals An Iron-Based Dehydration Catalyst for Selective Formation of Styrene

ACS Catalysis ◽  
2021 ◽  
pp. 10885-10891
Author(s):  
Olaf Nachtigall ◽  
Andrew I. VanderWeide ◽  
William W. Brennessel ◽  
William D. Jones
Keyword(s):  
Iron Based ◽  
Selective Formation

scholarly journals Effect of Ni(NO3)2 Pretreatment on the Pyrolysis of Organsolv Lignin Derived from Corncob Residue

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 23
Author(s):  
Wenli Wang ◽  
Yichen Liu ◽  
Yue Wang ◽  
Longfei Liu ◽  
Changwei Hu
Keyword(s):  
Sustainable Development ◽  
Fixed Bed ◽  
Value Added ◽  
Bio Oil ◽  
Fuels And Chemicals ◽  
Gas Products ◽  
Work Samples ◽  
Nickel Species ◽  
The Impact ◽  
Selective Formation

The thermal degradation of lignin for value-added fuels and chemicals is important for environment improvement and sustainable development. The impact of pretreatment and catalysis of Ni(NO3)2 on the pyrolysis behavior of organsolv lignin were studied in the present work. Samples were pyrolyzed at 500 ∘C with an upward fixed bed, and the characteristics of bio-oil were determined. After pretreatment by Ni(NO3)2, the yield of monophenols increased from 23.3 wt.% to 30.2 wt.% in “Ni-washed” and decreased slightly from 23.3 wt.% to 20.3 wt.% in “Ni-unwashed”. Meanwhile, the selective formation of vinyl-monophenols was promoted in “Ni-unwashed”, which indicated that the existence of nickel species promoted the dehydration of C-OH and breakage of C-C in pyrolysis. In comparison with “Water”, HHV of bio-oil derived from “Ni-unwashed” slightly increased from 27.94 mJ/kg to 28.46 mJ/kg, suggesting that the lowering of oxygen content in bio-oil is associated with improved quality. Furthermore, the content of H2 in gas products dramatically increased from 2.0% to 7.6% and 17.1%, respectively.

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