16982-89-1

Upstream product

• 57056-88-9 1-(but-3-en-1-yloxy)-2-iodobenzene 
• 108-98-5 thiophenol 
• 155304-06-6 1-(but-3-yn-1-yloxy)-2-iodobenzene 
• 2653-89-6 4-phenoxy-1-butene 
• 401916-78-7 1-(2-bromoethoxy)-2-vinylbenzene 
• 762-04-9 Diethyl phosphonate 
• 22409-85-4 4-phenoxybutan-2-one 
• 87280-00-0 1‐bromo‐2‐(but-3‐en‐1‐yloxy)benzene 

Relevant academic research and scientific papers

Photo-induced radical cyclization of aromatic halides with sodium borohydride

Direct UV irradiation of ortho-allyloxy- and ortho-but-3-enyloxy-iodo- and bromo-benzenes in the presence of NaBH4 or NaBH3CN gave radical cyclization products in high yield. Georg Thieme Verlag Stuttgart.

Anions from dihydro substituted ethyl benzoates and quinoline. New hydrogen donors for tin-free radical chemistry

The anions of substituted dihydro ethyl benzoates and quinoline are very good hydrogen donors to radicals in liquid ammonia and DMSO. With 4-substituted dihydro ethyl benzoates the rate of hydrogen transfer decreases and excellent yields of products are obtained by 6-exo ring closure reaction followed by reduction.

Radical Hydrodehalogenation of Aryl Bromides and Chlorides with Sodium Hydride and 1,4-Dioxane

A practical method for radical chain reduction of various aryl bromides and chlorides is introduced. The thermal process uses NaH and 1,4-dioxane as reagents and 1,10-phenanthroline as an initiator. Hydrodehalogenation can be combined with typical cyclization reactions, proving the nature of the radical mechanism. These chain reactions proceed by electron catalysis. DFT calculations and mechanistic studies support the suggested mechanism.

Synthesis of tetralin and chromane derivatives via In-catalyzed intramolecular hydroarylation

In(OTf)3 was found to be an effective catalyst for the cyclization of ω-aryl-1-alkenes to form tetralin and chromane derivatives. Compared with the known Ru-catalyzed version, the In-catalyzed intramolecular cyclization was found to give higher yields and cleaner reactions in some cases. The use of cheaper indium salts instead of the expensive noble metal Ru can be advantageous when the reaction is run on a large scale.

Exploring SmBr2-, SmI2-, and YbI2-mediated reactions assisted by microwave irradiation

The use of microwave heating in lanthanide(II) halide (LnX2 = SmBr2, SmI2, and YbI2) mediated reduction and coupling reactions has been investigated for a variety of functional groups including α,β-unsaturated esters, aldehydes, ketones, imines, and alkyl halides. Good to quantitative transformations were obtained within a few minutes without the addition of any co-solvents, such as hexamethyl phosphoramide (HMPA). The redox potential of YbI2 in tetrahydrofuran (THF) has been determined as -1.02± 0.05 V (versus Ag/AgNO3) by cyclic voltammetry. A large selectivity difference in various reactions was observed depending on the redox potential of the LnX2 reagent. The more powerful reductant, SmBr2, afforded mainly pinacol-coupling products of ketones whereas the weaker reductant YbI2 afforded mainly reduction products. The results indicate that the reducing power of LnX 2 has a large impact on not only the pinacol coupling/reduction product ratio of ketones but also on other substrates in which there are competing coupling and reduction reactions. The use of in situ generated LnX2 has also been explored and proven useful in many of these reactions.

Diastereoselective intramolecular SmI2-H2O-amine mediated couplings

The effectiveness of SmI2-H2O-amine mixture for intramolecular couplings was discussed. Diastereoselectivities in the coupling of O-cyclohexanyliodophenol derivatives were provided into heterocycles. The amount of coupled product improved significantly as SmI2, the substrate and amine were premixed followed by a gradual addition of water.

Reactivity of aryl and vinyl radicals: Abstraction of hydrogen atom or reaction with a nucleophile

The reactivities of aryl and vinyl radicals, two fundamental transient intermediates, have been investigated with respect to two elementary processes: H-atom abstraction and reaction with a nucleophile (Y-, in the SRN1 reaction). The radicals of interest were generated from haloarene or haloethene precursors, either by use of the Bu3SnH/AIBN system or by photostimulated electron transfer from a nucleophile, and the partition of the intermediate radical between competing pathways was investigated. Use both of indirect methods (such as the study of the reaction products in competition experiments; use of a radical-clock probe) and of direct ones (such as the detection of the radicals by flash photolysis experiments) enabled the following rate constants to be obtained (all values in m-l.s-1 at 25 °C). For phenyl type radicals, the rate constants for H abstraction (kH) from the solvents Me2SO (2.8.106) and CH3CN (6.7.106) and the rate constant for combination with a nucleophile (ky) such as Me3CCOCH2- ion (3.3.109) were determined. For vinyl radical Ph2C=C(.)Ph (7.), the kH values from Me2SO (1.1.105), CH3CN (1.2.105), Bu3SnH(7.5-108), and (Me3Si)3SiH (1.6.109) and the ky values with Me3CCOCH2- (3.9.107), (EtO)2PO(2.8.106), and PhS- (1.9.107) ions were determined. Semiempirical calculations confirmed a stabilization of radical 7.by the α-Ph substituent (ca. 8 kcal/mol), and provided the BDE of the C-Y bond for the vinylic substitution products of 7.. Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002).

Olefins turned alkylating agents: Diastereoselective intramolecular Zr-catalyzed olefin alkylations

(Equation Presented) 62% yield; 12 : 1 syn : anti The first examples of intramolecular Zr-catalyzed electrophilic alkylation of aryl olefins are disclosed. Substituted carbo-and heterocycles are prepared efficiently and diastereoselectively.

Determination of rate constants for the reaction of aryl radicals with enolate ions

The rate of ring closure (kC) of o-(ω-alkenyl)aryl radicals by means of an intramolecular attack of the intermediate phenyl-type radical at the tethered double bond was found to be 4.2 × 108 S-1 (for 1?) and 7.6×107 S-1 (for 8?), both being 6-exo-trig processes, and 9.6 × 109 S-1 for the 5-exo-trig process of 3?. The kC rate constant of these radicals was calibrated with respect to a known rate of H-atom abstraction (kH). The photostimulated SRN1 reactions of radical clock precursor 1 with anions PhS- and (EtO)2PO- in Me2SO at 25 °C provided the rates of addition of these nucleophiles (kY) to intermediate 1? (3.2 × 108 and 2.5 × 109 M-1 S-1, respectively). In contrast, the analogous reaction of a ketone enolate ion with precursor 1 did not take the expected SRN1 course; instead an elimination reaction was favoured. Similarly, the reactions of radical clock precursors 3 or 8 with the enolate ion failed. However, investigation of the distribution of 9-anthracenyl (11?) or 1-naphthyl (12?) radicals between two competing reactions, namely combination with a nucleophile and H abstraction from the solvent (Me2SO), was successful and eventually enabled us to find the kY values for the addition of the enolate ion to these two aryl radical intermediates (4.4 × 108 and 2.9 × 109 M-1 S-1, respectively).

Rearrangement Alkyl Phenyl Ethers to Alkylphenols in the Presence of Cation-exchanged Montmorillonite (Mn+-Mont)

The rearrangement of alkyl phenyl ethers such as 4-phenoxybutan-2-one 1, 1-phenoxybutane 2a, 2-phenoxybutane 2b, 2-methyl-2-phenoxypropane 2c and phenoxycyclohexane 2d have been investigated in the presence of cation-exchanged montmorilonite (Mn+-mont; Mn+ = Zr4+, Al3+, Fe3+ and Zn2+).The ether 1 rearranged to 4-(4-hydroxyphenyl)butan-2-one 3 (raspberry ketone), the odour source of rasprerry, in 16-34percent GLC yield, where Zn2+-mont was the most effective catalyst.Similarly, other ethers 2a-d rearranged to the corresponding alkylphenols in up to 75percent isolated yield with good product selectivity, Al3+-mont being the catalyst of choice.Al3+-Mont was regenerated and resulted in the rearrangement of 2b, 2c and 2d.