A new approach to .alpha.,.alpha.-difluoro-functionalized esters
摘要:
The addition reaction of iododifluoroacetates to alkenes is initiated by copper powder (10-20 mol %) at 50-60-degrees-C. Both terminal and internal alkenes give good yields of adducts. The reaction is also applicable to alkenes containing a variety of functional groups, such as epoxy, hydroxy, ketone, ester, and phosphonate moieties. This reaction can be carried out either neat or in solvents such as hexane, benzene, acetonitrile, DMF, DMSO, and HMPA and is suppressed by p-dinitrobenzene and di-tert-butyl nitroxide. A single electron transfer initiated radical mechanism is proposed. In the presence of nickel dichloride hexahydrate, reduction of the adducts with zinc in moist THF provides the corresponding alpha,alpha-difluoro esters in good yields.
Diethylzinc-Mediated Radical 1,2-Addition of Alkenes and Alkynes
作者:Xin Li、Songtao He、Qiuling Song
DOI:10.1021/acs.orglett.1c00669
日期:2021.4.16
A novel diethylzinc-mediated radical 1,2-addition of perfluoroalkyl iodides to unactivatedalkenes and alkynes is presented, which demonstrates a novel way to generate an ethyl difluoroacetate radical. This method is highly efficient and gives full conversions of the substrates, high yields of the products, and negligible byproducts and requires no column chromatography purifications. The mild conditions
A general and green fluoroalkylation reaction promoted <i>via</i> noncovalent interactions between acetone and fluoroalkyl iodides
作者:Ting Mao、Ming-Jian Ma、Liang Zhao、De-Pu Xue、Yanbo Yu、Jiwei Gu、Chun-Yang He
DOI:10.1039/c9cc09517a
日期:——
The first example of visible light promoted fluoroalkylation reactions initiated via noncovalent interactions between acetone and fluoroalkyl iodides is presented. The reaction system features synthetic simplicity, mild reaction conditions without any photoredox catalyst, and high functional group tolerance. A wide range of substrate scopes such as alkenes, alkynes and (hetero)arenes were all compatible
Metal-Free Iodoperfluoroalkylation: Photocatalysis versus Frustrated Lewis Pair Catalysis
作者:Constantin Czekelius、Lucas Helmecke、Michael Spittler、Bernd M. Schmidt
DOI:10.1055/s-0040-1707232
日期:2021.1
Professor Rolf Huisgen Abstract A comparison of two catalytic, metal-free iodoperfluoroalkylation protocols is presented. FrustratedLewispairs [ t Bu3P/B(C6F5)3] or phosphines/phosphites under visible light irradiation efficiently mediate the functionalization of non-activated alkenes and alkynes. A comprehensive account of the corresponding substrate scopes as well as insights into the mechanistic details
纪念Rolf Huisgen教授 抽象 比较了两种催化的,无金属的碘代氟烷基化方案。沮丧的路易斯对[ t Bu 3 P / B(C 6 F 5)3 ]或膦/亚磷酸盐在可见光辐射下有效地介导了未活化的烯烃和炔烃的官能化。提供了对相应底物范围的全面介绍,以及对两种反应途径的机理细节的见解。