Consecutive cross-coupling reactions of 2,2-difluoro-1-iodoethenyl tosylate with boronic acids: efficient synthesis of 1,1-diaryl-2,2-difluoroethenes
作者:Ju Hee Kim、Su Jeong Choi、In Howa Jeong
DOI:10.3762/bjoc.9.286
日期:——
The cross-coupling reactions of 2,2-difluoro-1-iodoethenyl tosylate (2) with 2 equiv of boronic acids in the presence of catalytic amounts of Pd(OAc)2 and Na2CO3 afforded the mono-coupled products 3 and 5 in high yields. The use of 4 equiv of boronic acids in the presence of catalytic amount of Pd(PPh3)2Cl2 and Na2CO3 in this reaction resulted in the formation of symmetrical di-coupled products 4 in high yields. Unsymmetrical di-coupled products 4 were obtained in high yields from the reactions of 3 with 2 equiv of boronic acids in the presence of catalytic amounts of Pd(OAc)2 and Na2CO3.
Direct α-Monofluoroalkenylation of Heteroatomic Alkanes via a Combination of Photoredox Catalysis and Hydrogen-Atom-Transfer Catalysis
作者:Hao Tian、Qing Xia、Qiang Wang、Jianyang Dong、Yuxiu Liu、Qingmin Wang
DOI:10.1021/acs.orglett.9b01491
日期:2019.6.21
In this study, a new C(sp3)–H monofluoroalkenylation reaction involving cooperative visible-light photoredoxcatalysis and hydrogen-atom-transfer catalysis to afford products generated by selective hydrogen abstraction and radical–radical cross-coupling was described. This mild, efficient reaction shows high regioselectivity for the α-carbon atoms of amines, ethers, and thioethers and thus allows the
Efficient Synthesis of 2,2-Diaryl-1,1-difluoroethenes via Consecutive Cross-Coupling Reactions of 2,2-Difluoro-1-tributylstannylethenyl <i>p</i>-Toluenesulfonate
作者:Seung Yeon Han、In Howa Jeong
DOI:10.1021/ol1024037
日期:2010.12.3
2,2-Difluoro-1-tributylstannylethenyl p-toluenesulfonate (2) was reacted with aryl iodides in the presence of 10 mol % of Pd(PPh3)4 and 10 mol % of CuI in DMF at 80 °C for 10−20 h to give the cross-coupled products 3 in 35−97% yields. Further coupling reaction of 3 with arylstannanes in the presence of 5 mol % of Pd(PPh3)4 and 3 equiv of LiBr in DMF at 100 °C for 2−24 h afforded the desired products
A novel method for the synthesis of 2,2-diaryl-1,1-difluoroethenes
作者:Ji Hoon Choi、In Howa Jeong
DOI:10.1016/j.tetlet.2007.12.028
日期:2008.2
β,β-Difluoro-α-phenylvinylstannane 3 was prepared in 60% yield from the reaction of β,β-difluoro-α-phenylvinylsulfone 2 with tributyltin hydride in refluxing benzene for 5 h. The cross-coupling reaction of 3 with aryl iodides bearing substituents such as proton, fluoro, chloro, bromo, methoxy, methyl, trifluoromethyl, and nitro on ortho, meta, para positions of the benzene ring in the presence of 10 mol %
Dehalogenative Cross-Coupling of <i>gem</i>-Difluoroalkenes with Alkyl Halides <i>via</i> a Silyl Radical–Mediated Process
作者:Hao Tian、Shaoxiang Yang、Xiaochen Wang、Wentao Xu、Yuxiu Liu、Yongqiang Li、Qingmin Wang
DOI:10.1021/acs.joc.1c01363
日期:2021.9.17
Mechanistic experiments showed that the products were generated by selective cross-coupling of aliphatic radicals with fluoroalkenyl radicals. Silyl radical-mediated halogen abstraction enabled the protocol to be used for the monofluoroalkenylation of a broad range of alkyl and heteroaryl halides. The protocol could be carried out on a gram scale and was applied to cholesterol, indicating its utility