71264-86-3Relevant academic research and scientific papers
Asymmetric Halocyclizations of 2-Vinylbenzyl Alcohols with Chiral FLPs
Han, Caifang,Feng, Xiangqing,Du, Haifeng
, p. 7325 - 7329 (2021/10/01)
By the use of a chiral frustrated Lewis pair (FLP) consisting of a chiral-diene-derived borane and tBu3P as the catalyst, an asymmetric halocyclization of 2-vinylbenzyl alcohols with NBS or NIS was successfully realized. A variety of optically active 1,3-dihydroisobenofuran derivatives were obtained in high yields with up to 87% ee and could be conveniently converted to other useful chiral compounds.
Copper-Catalyzed Modular Amino Oxygenation of Alkenes: Access to Diverse 1,2-Amino Oxygen-Containing Skeletons
Hemric, Brett N.,Chen, Andy W.,Wang, Qiu
, p. 1468 - 1488 (2019/01/25)
Copper-catalyzed alkene amino oxygenation reactions using O-acylhydroxylamines have been achieved for a rapid and modular access to diverse 1,2-amino oxygen-containing molecules. This transformation is applicable to the use of alcohols, carbonyls, oximes, and thio-carboxylic acids as nucleophiles on both terminal and internal alkenes. Mild reaction conditions tolerate a wide range of functional groups, including ether, ester, amide, carbamate, and halide. The reaction protocol allows for starting with free amines as the precursor of O-benzoylhydroxylamines to eliminate their isolation and purification, contributing to broader synthetic utilities. Mechanistic investigations reveal the amino oxygenation reactions may involve distinct pathways, depending on different oxygen nucleophiles.
Metal-Free Arylation-Lactonization Sequence of γ-Alkenoic Acids Using Anilines as Aryl Radical Precursors
Felipe-Blanco, Diego,Gonzalez-Gomez, Jose C.
, p. 7735 - 7744 (2019/12/24)
The presence of salicylic acid (10 mol-%) and H2O (10 equiv.) significantly improves the arylation-lactonization sequence of γ-alkenoic acids with in situ formed diazonium salts (from bench stable anilines). The reaction is finished in less than 5 h without thermal or photochemical activation, giving access to a variety of γ,γ-disubstituted butyrolactones. The protocol is user-friendly and can be used at gram-scale or adapted to transform alkenols into phthalanes. Control experiments revealed that aryl radicals participate in the reaction and a plausible mechanism is proposed to include this and other mechanistic investigations, for the catalyzed and the background reaction.
Synthesis of isothiochromenes and 1,3-dihydrobenzo[c]thiophenes by iodine- and hydrobromic acid-mediated cyclizations of o-[(tert-butylsulfanyl)methyl)]styrenes
Kobayashi, Kazuhiro,Ueyama, Takuma,Horiuchi, Mai
, p. 2065 - 2079 (2017/11/21)
Methods for the syntheses of 4-substituted isothiochromenes and 1,1-disubstituted 1,3-dihydrobenzo[c]thiophenes have been developed. Thus, treatment of α-substituted o-[(tert-butylsulfanyl)methyl]styrenes, derived from α-substituted o-bromostyrenes using
Copper-catalysed cyanoalkylative cycloetherification of alkenes to 1,3-dihydroisobenzofurans: development and application to the synthesis of citalopram
Ha, Tu M.,Wang, Qian,Zhu, Jieping
, p. 11100 - 11103 (2016/09/19)
A copper-catalysed cyanoalkylative cycloetherification of alkenes was developed. Heating a solution of substituted (2-vinylphenyl)methanol in MeCN/MeOH (v/v 7/3) in the presence of a catalytic amount of copper(ii) tetrafluoroborate hydrate [Cu(BF4)2·6H2O], bathophenanthroline, K3PO4, BnOH and (tBuO)2 afforded 1,3-dihydroisobenzofurans (phthalanes) via formation of one C(sp3)-C(sp3) and one C(sp3)-O bonds. A concise synthesis of citalopram, a marketed anti-depressant drug, was accomplished by applying this novel synthetic transformation.
