Au@Pd Bimetallic Nanocatalyst for Carbon–Halogen Bond Cleavage: An Old Story with New Insight into How the Activity of Pd is Influenced by Au

2018 ◽  
Vol 52 (7) ◽  
pp. 4244-4255 ◽  
Author(s):  
Rui Liu ◽  
Hui-min Chen ◽  
Li-ping Fang ◽  
Cuihong Xu ◽  
Zuoliang He ◽  
...  
Keyword(s):  
Halogen Bond ◽  
Bond Cleavage ◽  
Bimetallic Nanocatalyst ◽  
Insight Into

The Crystal Structure ofBacillus cereusPhosphonoacetaldehyde Hydrolase:  Insight into Catalysis of Phosphorus Bond Cleavage and Catalytic Diversification within the HAD Enzyme Superfamily†,‡

Biochemistry ◽  
2000 ◽  
Vol 39 (34) ◽  
pp. 10385-10396 ◽  
Author(s):  
Marc C. Morais ◽  
Wenhai Zhang ◽  
Angela S. Baker ◽  
Guofeng Zhang ◽  
Debra Dunaway-Mariano ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Bond Cleavage ◽  
Enzyme Superfamily ◽  
Insight Into

scholarly journals Computational study on the mechanism of metal-free photochemical borylation of aryl halides

2021 ◽  
Author(s):  
Chenhao Tu ◽  
Nana Ma ◽  
Qingli Xu ◽  
Wenyue Guo ◽  
Lanxin Zhou ◽  
...  
Keyword(s):  
Density Functional ◽  
Uv Light ◽  
Computational Study ◽  
Halogen Bond ◽  
Bond Cleavage ◽  
Aryl Halides ◽  
Homolytic Cleavage ◽  
Functional Theory ◽  
Aryl Radicals

C-radical borylation is an significant approach for the construction of carbon−boron bond. Photochemical borylation of aryl halides successfully applied this strategy. However, precise mechanisms, such as the generation of aryl radicals and the role of base additive(TMDAM) and water, remain controversy in these reactions. In this study, photochemical borylation of aryl halides has been researched by density functional theory (DFT) calculations. Indeed, the homolytic cleavage of the C−X bond under irradiation with UV-light is a key step for generation of aryl radicals. Nevertheless, the generation of aryl radicals may also undergo the process of single electron transfer and the heterolytic carbon-halogen bond cleavage sequence, and the latter is favorable during the reaction.

Hot Electron-Induced Carbon–Halogen Bond Cleavage Monitored by in Situ Surface-Enhanced Raman Spectroscopy

2019 ◽  
Vol 123 (27) ◽  
pp. 16741-16746 ◽  
Author(s):  
Ping Jiang ◽  
Yueyue Dong ◽  
Ling Yang ◽  
Yaran Zhao ◽  
Wei Xie
Keyword(s):  
Raman Spectroscopy ◽  
Halogen Bond ◽  
Bond Cleavage ◽  
Surface Enhanced Raman Spectroscopy ◽  
Hot Electron ◽  
Surface Enhanced ◽  
Surface Enhanced Raman

Insight into the halogen-bond nature of noble gas-chlorine systems by molecular beam scattering experiments, ab initio calculations and charge displacement analysis

2019 ◽  
Vol 21 (14) ◽  
pp. 7330-7340 ◽  
Author(s):  
Francesca Nunzi ◽  
Diego Cesario ◽  
Leonardo Belpassi ◽  
Francesco Tarantelli ◽  
Luiz F. Roncaratti ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Molecular Beam ◽  
Halogen Bond ◽  
Noble Gas ◽  
Molecular Beam Scattering ◽  
Beam Scattering ◽  
Charge Displacement ◽  
Insight Into

A weak halogen bond, together with charge transfer from a noble gas to Cl2, characterizes the intermolecular interaction between a noble gas atom and Cl2 in a collinear configuration.

Iminyl-Radical-Triggered C–C Bond Cleavage of Cycloketone Oxime Derivatives: Generation of Distal Cyano-Substituted Alkyl Radicals and Their Functionalization

Synthesis ◽  
2020 ◽  
Vol 52 (11) ◽  
pp. 1585-1601 ◽  
Author(s):  
Tiebo Xiao ◽  
Lei Zhou ◽  
Hongtai Huang ◽  
Devireddy Anand
Keyword(s):  
Halogen Bond ◽  
Cyano Group ◽  
Bond Cleavage ◽  
Bond Formation ◽  
Radical Reaction ◽  
Building Blocks ◽  
Aromatic Rings ◽  
Organometallic Reagents ◽  
Alkyl Radicals ◽  
Oxime Derivatives

Alkyl nitriles are versatile building blocks in organic synthesis because the cyano group can be easily converted into other functional groups. Iminyl-radical-triggered C–C bond cleavage of cycloketone oxime­ derivatives provides a practical route to access distal cyano-substituted alkyl radicals, which has given chemists a new radical reaction platform for the synthesis of diverse alkyl nitriles. This review provides an overview of various types of radical cyanoalkylation via ring opening of cycloketone oxime derivatives.1 Introduction2 C–C Bond Formation2.1 Alkenes as Radical Acceptors2.2 Aromatic Rings as Radical Acceptors2.3 Organometallic Reagents as Radical Acceptors2.4 Cyanoalkyl-Radical-Triggered Cyclization Reactions2.5 Miscellaneous3 C–Heteroatom Bond Formation3.1 C–O Bond Formation3.2 C–N Bond Formation3.3 C–S Bond Formation3.4 C–Halogen Bond Formation3.5 C–B Bond Formation4 Conclusion

Facile chelate-assisted carbon-halogen bond cleavage at tungsten(0)

1987 ◽  
Vol 6 (9) ◽  
pp. 1995-1996 ◽  
Author(s):  
Thomas G. Richmond ◽  
Margaret A. King ◽  
Eric P. Kelson ◽  
Atta M. Arif
Keyword(s):  
Halogen Bond ◽  
Bond Cleavage

Carbon-halogen bond cleavage energies of polyhaloalkyl radical anions in solution

1996 ◽  
Vol 37 (9) ◽  
pp. 1457-1460 ◽  
Author(s):  
Jin-Pei Cheng ◽  
Zirong Zheng
Keyword(s):  
Halogen Bond ◽  
Bond Cleavage ◽  
Radical Anions

scholarly journals The X-Ray Structure of the Haloalcohol Dehalogenase HheA from Arthrobacter sp. Strain AD2: Insight into Enantioselectivity and Halide Binding in the Haloalcohol Dehalogenase Family

2006 ◽  
Vol 188 (11) ◽  
pp. 4051-4056 ◽  
Author(s):  
René M. de Jong ◽  
Kor H. Kalk ◽  
Lixia Tang ◽  
Dick B. Janssen ◽  
Bauke W. Dijkstra
Keyword(s):  
Tertiary Structure ◽  
Halogen Bond ◽  
Environmental Pollutants ◽  
Binding Pocket ◽  
Catalytic Triad ◽  
Side Chain ◽  
Structural Determinants ◽  
Substrate Binding Pocket ◽  
X Ray ◽  
Insight Into

ABSTRACT Haloalcohol dehalogenases are bacterial enzymes that cleave the carbon-halogen bond in short aliphatic vicinal haloalcohols, like 1-chloro-2,3-propanediol, some of which are recalcitrant environmental pollutants. They use a conserved Ser-Tyr-Arg catalytic triad to deprotonate the haloalcohol oxygen, which attacks the halogen-bearing carbon atom, producing an epoxide and a halide ion. Here, we present the X-ray structure of the haloalcohol dehalogenase HheAAD2 from Arthrobacter sp. strain AD2 at 2.0-Å resolution. Comparison with the previously reported structure of the 34% identical enantioselective haloalcohol dehalogenase HheC from Agrobacterium radiobacter AD1 shows that HheAAD2 has a similar quaternary and tertiary structure but a much more open substrate-binding pocket. Docking experiments reveal that HheAAD2 can bind both enantiomers of the haloalcohol substrate 1-p-nitrophenyl-2-chloroethanol in a productive way, which explains the low enantiopreference of HheAAD2. Other differences are found in the halide-binding site, where the side chain amino group of Asn182 is in a position to stabilize the halogen atom or halide ion in HheAAD2, in contrast to HheC, where a water molecule has taken over this role. These results broaden the insight into the structural determinants that govern reactivity and selectivity in the haloalcohol dehalogenase family.

Visible Light-Promoted Metal-Free Reduction of Organohalides by 2-Naphthyl or 2-Hydroxynaphthyl-Substituted 1,3-Dimethylbenzimidazolines

2015 ◽  
Vol 68 (11) ◽  
pp. 1648 ◽  
Author(s):  
Eietsu Hasegawa ◽  
Kazuma Mori ◽  
Shiori Tsuji ◽  
Kazuki Nemoto ◽  
Taku Ohta ◽  
...  
Keyword(s):  
Visible Light ◽  
Halogen Bond ◽  
Light Emitting Diode ◽  
Bond Cleavage ◽  
Ring Expansion ◽  
Single Electron Transfer ◽  
Reduction Reactions ◽  
Light Emitting ◽  
Reducing Ability ◽  
Carbon Radicals

The visible light-promoted reduction reactions of some organohalides were investigated using 2-aryl-1,3-dimethylbenzimidazolines (Ar-DMBIH) possessing 2-naphthyl or 2-hydroxynaphthyl substituents. In these reduction reactions, single-electron transfer from photo-excited Ar-DMBIH, attained by Xe lamp irradiation through an appropriate glass-filter (λ > 390 nm), to the halide substrates leads to the carbon–halogen bond cleavage, followed by the rearrangements of the formed carbon radicals such as 5-exo hexenyl cyclization and the Dowd–Beckwith ring expansion. Addition of 1,8-diazabicyclo[5.4.0]undec-7-ene was found to enhance the reducing ability of hydroxynaphthyl-substituted DMBIH. A household white light-emitting diode was also used as a light source for these reactions.

Sign in / Sign up

Export Citation Format

Share Document