Phase-Transfer Catalyzed Nucleophilic Addition of Arylalkanenitrile Carbanions to Substituted Propenylarenes
作者:Wojciech Lasek、Mieczysław Makosza
DOI:10.1055/s-1993-35865
日期:——
Phenylacetonitrile and 2-phenylalkanenitriles react under phase transfer catalysis conditions with 2-propenylanisoles containing electron-withdrawing substituents (or their corresponding precursors, 2-allylanisoles) via the Michael addition pathway to give substituted 4-aryl-2-phenylbutyronitriles.
Catalyst-Free 1,2-Dibromination of Alkenes Using 1,3-Dibromo-5,5-dimethylhydantoin (DBDMH) as a Bromine Source
作者:Lei Wang、Lele Zhai、Jinyan Chen、Yulin Gong、Peng Wang、Huilin Li、Xuegong She
DOI:10.1021/acs.joc.1c02906
日期:2022.3.4
source. This reaction proceeds under mild reaction conditions without the use of a catalyst and an external oxidant. Various sorts of alkene substrates are transformed into the corresponding 1,2-dibrominated products in good to excellent yields with broad substrate scope and exclusive diastereoselectivity. This method offers a green and practical approach to synthesize vicinaldibromide compounds.
HALOGEN MIGRATION AND ELIMINATION IN THE CLAISEN REARRANGEMENT OF ALLYL 2,6-DIHALOPHENYL ETHERS
作者:E. Piers、R. K. Brown
DOI:10.1139/v63-430
日期:1963.12.1
A study has been made of some factors affecting the migration or elimination of halogen in the Claisenrearrangement of allyl 2,6-dihalophenyl ethers.In the thermal rearrangement of allyl 2,6-dichlorophenyl ether, carried out in a number of solvents of different dielectric constant, halogen migration proceeds somewhat better in highly polar solvents. However, a competitive reduction to the monohalogenated
1,3-dibromo-5,5-dimethylhydantoin (DBDMH) is a useful and easy to handle reagent for bromination of various aromatic derivatives substituted with electron donating groups. In the presence of trimethylsilyltrifluoromethanesulfonate, DBDMH showed increased reactivity, and in one case, the reaction followed another pathway, suggesting an alternative mechanism.
Synthesis of 2-bromomethyl-2,3-dihydrobenzofurans from 2-allylphenols enabled by organocatalytic activation of <i>N</i>-bromosuccinimide
作者:Carolina G. Furst、Paulo H. P. Cota、Taciano A. dos Santos Wanderley、Eduardo E. Alberto
DOI:10.1039/d0nj03432k
日期:——
compounds that can be obtained by an intramolecular reaction between 2-allylphenols and a bromenium ion source (Br+). Due to the ineffectiveness of the safe and easy-to-handle brominating agent N-bromosuccinimide (NBS) to deliver the desired products, a catalytic process using a mixture of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and acetic acid was conceived. We hypothesized that this catalytic system