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• 673-32-5 1-Phenylprop-1-yne 
• 6084-17-9 2-chloro-1-phenylpropan-1-one 
• 64-19-7 acetic acid 
• 6202-57-9 2-Chlor-3-methyl-2-phenyloxiran 
• 133610-79-4 3-α-methyl-α-chlorobenzyl-3-chlorodiazirine 

Relevant academic research and scientific papers

Preparation of vincinal hetero 1,2-dihalo-olefins by using aqueous hydrohalic acid

An efficient simple method was developed to prepare hetero E-1,2-dihaloolefins from mono- or disubstituted alkynes, in which, NXS (X = Br, I) was utilized as the electrophilic reagents and aqueous hydrohalic acid as the nucleophile. Moreover, Z-type dihalogenation olefins could be obtained from the terminal silylacetylene.

Regio- and Stereoselective Synthesis of 1,2-Dihaloalkenes Using In-Situ-Generated ICl, IBr, BrCl, I2, and Br2

We describe a catalyst-free 1,2-trans-dihalogenation of alkynes with an unprecedented substrate scope and exclusive regio- and stereoselectivity. This versatile dihalogenation system—a combination of NX1S electrophile and alkali metal halide (MX2) in acetic acid—is applicable for diverse categories of alkynes (electron-rich or poor alkynes, internal and terminal alkynes, or heteroatoms such as O-, N-, S-substituted alkynes). The hydrogen bonding donor solvent acetic acid is essential for the in-situ generation of X1X2 electrophile, including ICl, IBr, BrCl, I2, and Br2. Haloalkenes are not only commonly found in biologically active natural products but also have been used extensively in cross-coupling reactions. More specifically, 1,2-dihaloalkenes are especially important synthons because of the presence of two synthetic handles that open a broad avenue to expeditiously generate multisubstituted alkenes. Dihalogenation of alkynes is a straightforward way to prepare 1,2-dihaloalkenes. However, existing alkyne dihalogenation methods either rely on the use of toxic reagents, such as IBr and ICl, lack regio- and stereoselectivity or have limited substrate scope. Thus, the development of a widely applicable and yet efficient alkyne dihalogenation method is still highly desired. Here, we have addressed the aforementioned issues based on an in-situ-generated dihalogenation of reagents, such as ICl and Ibr, by using the readily available N-halosuccinimide (NXS) and alkali metal halides as halogen sources. Our method offers an unprecedented substrate scope, the regio- and stereoselectivity for the synthesis of 1,2-dihaloalkenes. Our simple and mild conditions might find wild applications in the preparation of high-value building blocks for medicines and materials. Dihaloalkenes are important raw materials for pharmaceutical and chemical industries. However, existing preparation methods suffer from a limited substrate scope as well as poor regio- and stereoselectivity. Furthermore, these methods often necessitate highly toxic reagents, such as Cl2, ICl, and BrCl. Our environmentally friendly 1,2-trans-dihalogenation is based on easy-handling halide sources, such as alkali metal halides. What is more, our method offers an unprecedented substrate scope, the regio- and stereoselectivity for the synthesis of 1,2-dihaloalkenes.

Reaction of Aromatic and Unsaturated Compounds with the Potassium Permanganate/HCI (HBr) Acetonitrile Reagent

Addition of hydrochloric or hydrobromic acid to a solution of potassium permanganate in acetonitrile produced a homogeneous mixture, which is suitable for laboratory chlorination or bromination, respectively. Aromatic compounds more reactive than alkylbenzenes can be chlorinated or brominated without additional catalyst. Alkenes and alkynes give the corresponding vicinal dihaloalkanes and vinyl halides. All reactions complete within two hours under mild condition (25-60 °C) with excellent to moderate yields.

Energy Barrier for 1,2-Chlorine Migration in α-Methyl-α-chlorobenzyl(chloro)carbene

An activation energy of 3.4 kcal mol-1 (1 cal = 4.184 J) was obtained for the 1,2-chlorine migration in α-methyl-α-chlorobenzyl(chloro)carbene.

ROLE OF THE POLYMER BACKBONE ON THE REACTIVITY OF POLYMER-SUPPORTED (DICHLOROIODO)BENZENE

Chlorination of iodinated crosslinked polystyrene with Cl2 gave polyaryliododichloride containing 1.1 mmol of active chlorine per gram of resin, while fluorination of the same iodinated resin with XeF2 gave polyaryliododifluoride, co

Halogen Epoxides, 3. Reactions of 2-Chloro- and 2,3-Dichlorooxiranes with Silver Tetrafluoroborate: Synthesis of α-Fluorinated Carbonyl Compounds

Reactions of chlorinated oxiranes with silver tetrafluoroborate in ether have been investigated.Substituted-2-chlorooxiranes (4a - e) afforded the corresponding α-fluorocarbonyl compounds (7a - e) as major products and the isomeric α-chlorocarbonyl compounds (8a - e) as minor products.Substituted 2,3-dichlorooxiranes (10, 14, 20, 24) yielded the isomeric α,α-dichloroketones (13, 19, 22, 26b, 29b) as well as the corresponding α-chloro-α-fluoroketones (12, 17, 21, 26a, 29a) and α,β-unsaturated α-chloroketones (18, 23, 27, 30).The course of the reaction was rationalized.Similar reaction with α-chloroketones and with α,α-dichloroketones succeeded only at substrates (8b, 35) in which the chlorine substituents were in benzylic positions.

Vinyl Cation Intermediates in Electrophilic Additions to Triple Bonds. 1. Chlorination of Arylacetylenes

The products of ionic addition of chlorine to phenylacetylene, β-methylphenylacetylene, 4-methylphenylacetylene, β-ethylphenylacetylene, and tolan have been investigated in anhydrous acetic acid.The major products are the α,β-dichlorostyrenes arising from simple 1,2-addition, but significant yields of solvent-incorporated products are also found.In some cases significant yields of β-chlorophenylacetylenes are found, presumably arising from an addition-elimination process.No products arising from addition of 2 mol of Cl2 were observed.The reactions are clearlynonstereospecific and show only weak stereoselectivity varying from predominant syn to predominant anti addition.However, the reactions are all completely regiospecific in the Markovnikov sense.In the presence of low concentrations of added salts such as lithium chloride, acetate, and perchlorate, the product distribution and stereochemistry are hardly affected.Only at high concentrations of these salts is there any significant change in product distribution.The second-order rates of addition have been measured for five additional phenyl-substituted compounds.The seven ring-substituted phenylacetylenes show an excellent correlation with ?+, giving a large negative ρ value (-4.19).The effects of β-substitution on the rate of chlorination are very small.The results are interpreted in terms of a simple Ad-E2 process, in which the rate-determining transition state is an open vinyl-cation-like species, with most of the positive charge being developed at Cα.The subsequent product-determining intermediate is considered to be a tight ion pair between an open α-phenylvinyl cation and a chloride counterion.This ion pair can react by ion-pair collapse, solvent attack, or internal proton elimination.Activation parameters determined for three of the above compounds show that the higher rates of chlorination (over bromination) of the acetylene system are due almost entirely to lower Δ H(excit.) values.