Addition of Iodonium Nitrate to Unsaturated Hydrocarbons

1971 ◽  
Vol 49 (3) ◽  
pp. 403-415 ◽  
Author(s):  
U. E. Diner ◽  
J. W. Lown
Keyword(s):  
Steric Hindrance ◽  
Room Temperature ◽  
Conjugated Dienes ◽  
Electrophilic Addition ◽  
Type Ii ◽  
Unsaturated Hydrocarbons ◽  
Nitrate Esters ◽  
Terminal Acetylenes ◽  
Markovnikov Addition

Iodonium nitrate in chloroform-pyridine at room temperature undergoes a trans stereospecific electrophilic addition to alkenes to form (i) iodoaliphatic nitrate esters, (ii) iodoalkane pyridinium nitrates, or (iii) alkene pyridinium iodides depending on the substrate. The addition is sensitive to steric hindrance effects and anti-Markovnikov addition is commonly encountered. In similar additions to conjugated dienes 1,2-additions in a Markovnikov fashion to form 1:1 adducts of type (ii) are the rule. Terminal acetylenes give alkynyl iodides in fair yield.

Investigation of the V4+-Centre in 6H- and 4H-SIC by the Method of Spectral-Hole Burning

1998 ◽  
Vol 512 ◽  
Author(s):  
C. Hecht ◽  
R. Kummer ◽  
A. Winnacker
Keyword(s):  
Electronic Properties ◽  
Room Temperature ◽  
Hole Burning ◽  
Band Offset ◽  
Spectral Hole Burning ◽  
Type Ii ◽  
Thermally Stable ◽  
Spectral Hole

ABSTRACTIn the context of spectral-hole burning experiments in 4H- and 6H-SiC doped with vanadium the energy positions of the V4+/5+ level in both polytypes were determined in order to resolve discrepancies in literature. From these numbers the band offset of 6H/4H-SiC is calculated by using the Langer-Heinrich rule, and found to be of staggered type II. Furthermore the experiments show that thermally stable electronic traps exist in both polytypes at room temperature and considerably above, which may result in longtime transient shifts of electronic properties.

Tyrosine-Selective Bioconjugation with Iminoxyl Radicals

2020 ◽  
Author(s):  
Katsuya Maruyama ◽  
Takashi Ishiyama ◽  
Yohei Seki ◽  
Kounosuke Oisaki ◽  
Motomu Kanai
Keyword(s):  
Reaction Time ◽  
Steric Hindrance ◽  
Room Temperature ◽  
Water Soluble ◽  
Light Irradiation ◽  
Sodium Ascorbate ◽  
Iminoxyl Radical ◽  
Short Reaction Time ◽  
Modified Peptides ◽  
The Stability

A novel Tyr-selective protein bioconjugation using the water-soluble persistent iminoxyl radical is described. The conjugation proceeded with high Tyr-selectivity and short reaction time under biocompatible conditions (room temperature in buffered media under air). The stability of the conjugates was tunable depending on the steric hindrance of iminoxyl. The presence of sodium ascorbate and/or light irradiation promoted traceless deconjugation, restoring the native Tyr structure. The method is applied to the synthesis of a protein-dye conjugate and further derivatization to azobenzene-modified peptides.

Interfacial luminescence in an InAs/InAsSbP isotype type II heterojunction at room temperature

2011 ◽  
Vol 45 (10) ◽  
pp. 1334-1338 ◽  
Author(s):  
M. M. Grigoryev ◽  
E. V. Ivanov ◽  
K. D. Moiseev
Keyword(s):  
Room Temperature ◽  
Type Ii

Synthesis and Characterization of β-Haloalkenyl-λ3-bromanes:  Stereoselective Markovnikov Addition of Difluoro(aryl)-λ3-bromane to Terminal Acetylenes

2005 ◽  
Vol 127 (30) ◽  
pp. 10460-10461 ◽  
Author(s):  
Masahito Ochiai ◽  
Yoshio Nishi ◽  
Takeshi Mori ◽  
Norihiro Tada ◽  
Takashi Suefuji ◽  
...  
Keyword(s):  
Synthesis And Characterization ◽  
Terminal Acetylenes ◽  
Markovnikov Addition

A Novel and Efficient Alkoxylselenenylation of Alkenes

2019 ◽  
Vol 41 (6) ◽  
pp. 1039-1039
Author(s):  
Yingguo Fang and Jie Yan Yingguo Fang and Jie Yan
Keyword(s):  
Room Temperature ◽  
Electrophilic Addition ◽  
New Method ◽  
Reaction Conditions ◽  
Selenium Species

A novel and efficient alkoxylselenenylation from alkenes, diselenides, and alcohols mediated by iodine is developed, with which a series of β-alkoxy selenides are synthesized. In this procedure, firstly, I2 reacts with diselenide to form in situ the active electrophilic selenium species RSeI, then following an electrophilic addition of it to alkenes provides β-alkoxy selenides with high regioselectivity and in good yields. This new method for achieving β-alkoxy selenides has some advantages over other methods such as using available and cheap iodine as the oxidizing species at room temperature, which makes this reaction has milder reaction conditions and simpler procedure.

Long-wavelength electroluminescence of InGaAs-capped type-II GaSb/GaAs quantum-rings at room temperature

2013 ◽  
Vol 378 ◽  
pp. 571-575 ◽  
Author(s):  
Wei-Hsun Lin ◽  
Kai-Wei Wang ◽  
Shih-Yen Lin ◽  
Meng-Chyi Wu
Keyword(s):  
Room Temperature ◽  
Type Ii ◽  
Quantum Rings ◽  
Long Wavelength

CuI/Et2NH-Catalyzed One-Pot Highly Efficient Synthesis of 1,4-Disubstituted 1,2,3-Triazoles in Green Solvent Glycerol

Synthesis ◽  
2018 ◽  
Vol 50 (11) ◽  
pp. 2191-2199 ◽  
Author(s):  
Yongde Zhao ◽  
Shengqiang Guo ◽  
Yang Zhou ◽  
Bencai Dai ◽  
Cuimeng Huo ◽  
...  
Keyword(s):  
Catalytic System ◽  
Sodium Azide ◽  
Room Temperature ◽  
Green Solvent ◽  
Efficient Synthesis ◽  
One Pot ◽  
Highly Efficient ◽  
Three Component Reaction ◽  
Efficient Route ◽  
Terminal Acetylenes

A concise one-pot three-component reaction of organic halides­, terminal acetylenes, and sodium azide provided an efficient route for the synthesis of 1,2,3-triazoles. A variety of 1,2,3-triazoles were prepared in good to excellent yields with green solvent glycerol. This procedure used CuI and diethylamine, which are two easily available reagents as the new catalytic system at room temperature.

Nanofibers and amorphous Ni/Al2O3 catalysts — effect of steric hindrance on hydrogenation performance

2019 ◽  
Vol 9 (17) ◽  
pp. 4510-4514 ◽  
Author(s):  
Zhanming Zhang ◽  
Kai Sun ◽  
Yuyao Ma ◽  
Qianhe Liu ◽  
Qingyin Li ◽  
...  
Keyword(s):  
Steric Hindrance ◽  
Room Temperature

The steric hindrance of nanofibrous Ni–Al2O3 catalyst can be effectively reduced compared with that of the amorphous Ni/γ-Al2O3 catalyst, which greatly increases the activity of furfural and HMF hydrogenation at room temperature.

scholarly journals Highly Efficient Synthesis of Hindered 3-Azoindoles via Metal-Free C–H Functionalization of Indoles

Synthesis ◽  
2020 ◽  
Vol 52 (04) ◽  
pp. 574-580
Author(s):  
Nicolas Jacob ◽  
Lucas Guillemard ◽  
Joanna Wencel-Delord
Keyword(s):  
Steric Hindrance ◽  
Room Temperature ◽  
Efficient Synthesis ◽  
Atom Economy ◽  
Photochromic Compounds ◽  
Metal Free ◽  
Highly Efficient ◽  
Simple Protocol ◽  
Potential Applications

Although 3-azoindoles have recently emerged as an appealing family of photoswitch molecules, the synthesis of such compounds has been poorly covered in the literature. Herein a high-yielding and operationally simple protocol is reported allowing the synthesis of 3-azoindoles, featuring important steric hindrance around the azo motif. Remarkably, this C–H coupling is characterized by excellent atom economy and occurs under metal-free conditions, at room temperature, and within few minutes, delivering the expected products in excellent yields (quantitatively in most of the cases). Accordingly, a library of new molecules, with potential applications as photochromic compounds, is prepared.

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