- Scalable, Metal- and Additive-Free, Photoinduced Borylation of Haloarenes and Quaternary Arylammonium Salts
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We report herein a simple, metal- and additive-free, photoinduced borylation of haloarenes, including electron-rich fluoroarenes, as well as arylammonium salts directly to boronic acids. This borylation method has a broad scope and functional group tolerance. We show that it can be further extended to boronic esters and carried out on gram scale as well as under flow conditions.
- Mfuh, Adelphe M.,Doyle, John D.,Chhetri, Bhuwan,Arman, Hadi D.,Larionov, Oleg V.
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supporting information
p. 2985 - 2988
(2016/03/19)
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- Highly efficient one-pot access to functionalized arylboronic acids via noncryogenic bromine/magnesium exchanges
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A general and convenient protocol for the electrophilic borylation of aryl Grignard reagents prepared from arylbromides by direct insertion of magnesium in the presence of LiCl or by Mg/Br exchange with iPrMgCl?LiCl has been developed. Various aryl boronic acids were synthesized in a straightforward manner in excellent yields at 0 °C.
- Leermann, Timo,Leroux, Frederic R.,Colobert, Francoise
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supporting information; experimental part
p. 4479 - 4481
(2011/10/09)
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- 2-, 3-, and 4-(Trifluoromethoxy)phenyllithiums: Versatile intermediates offering access to a variety of new organofluorine compounds
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Consecutive treatment of (trifluoromethoxy)benzene with sec-butyllithium and electrophilic reagents affords previously inaccessible ortho-substituted derivatives in generally excellent yields. 2-(Trifluoromethoxy)phenyllithium acts as the key intermediate. The 3- and 4-isomers can readily be generated from the corresponding 3- and 4-bromo precursors by halogen-metal interconversion with butyllithium or tertbutyllithium. Upon trapping of the 2-, 3- and 4-(trifluoromethoxy)phenyllithiums with 11 different electrophiles the expected products were formed in generally high yields. Only the attempted nucleophilic addition of 2-(trifluoromethoxy)phenyllithium to oxirane did not succeed. This failure is tentatively attributed to a lowering of the nucleophilicity by fluorine-lithium interactions. Conformationally restricted analogs - i.e., 2,2-difluoro-1,3-benzodioxol-4-phenyllithium and its 5-fluoro- and 5-bromo-substituted congeners - did indeed react smoothly with oxirane, affording the adducts in ordinary yields.
- Castagnetti, Eva,Schlosser, Manfred
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p. 691 - 695
(2007/10/03)
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