- Aerobic Visible-Light-Driven Borylation of Heteroarenes in a Gel Nanoreactor
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Heteroarene boronate esters constitute valuable intermediates in modern organic synthesis. As building blocks, they can be further applied to the synthesis of new materials, since they can be easily transformed into any other functional group. Efforts toward novel and efficient strategies for their preparation are clearly desirable. Here, we have achieved the borylation of commercially available heteroarene halides under very mild conditions in an easy-to-use gel nanoreactor. Its use of visible light as the energy source at room temperature in photocatalyst-free and aerobic conditions makes this protocol very attractive. The gel network provides an adequate stabilizing microenvironment to support wide substrate scope, including furan, thiophene, selenophene, and pyrrole boronate esters.
- Herrera-Luna, Jorge C.,Diaz Diaz, David,Abramov, Alex,Encinas, Susana,Jimenez, M. Consuelo,Perez-Ruiz, Raul
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supporting information
p. 2320 - 2325
(2021/04/05)
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- Conformationally stable peptide macrocycles assembled using the Petasis borono-Mannich reaction
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Macrocyclization of linear peptide precursors using the Petasis borono-Mannich reaction affords a diverse range of macrocycles with an endocyclic amine. Analysis of the corresponding macrocyclic structures underscores that the hydrogen bond between an endocyclic amine and the adjacent amide NH is a powerful control element for conformationally homogenous peptide macrocycles.
- Yamaguchi, Akitake,Kaldas, Sherif J.,Appavoo, Solomon D.,Diaz, Diego B.,Yudin, Andrei K.
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supporting information
p. 10567 - 10570
(2019/09/06)
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- Highly Lewis Acidic Arylboronate Esters Capable of Colorimetric Turn-On Response
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A series of boronate-π-acceptor compounds containing different types of π bridges (1,4-phenylen or thien-2,5-diyl or furan-2,5-diyl) that link the switchable boronate ester group with the efficient TCF acceptor group (TCF=2-dicyanomethylen-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran) has been synthesized. A TCF chromophore of this type undergoes transition to a donor-π-acceptor compound upon coordination of Lewis bases at the Lewis acidic boron center, which is accompanied by an enhanced intramolecular charge-transfer interaction. The Lewis acid character has been investigated by spectroscopic measurements (UV/Vis, NMR spectroscopies) as well as DFT and ab initio-based calculations. It is shown that the TCF acceptor group and thiophene or furan π-bridges directly bound to the boron atom cooperatively increase the Lewis acidity. UV/Vis titration experiments confirm fluoride binding constants in the range of up to 108 M-1 in CH2Cl2. In addition to the strong boron fluoride binding motif, Lewis interactions also occur with weaker Lewis bases, such as pyridine or aliphatic alcohols. The unique combination of chromophoric and Lewis acidic properties is responsible for the intense colorimetric turn-on response detectable after complex formation. Push me, pull you: The interplay between the strongly electron-withdrawing TCF acceptor group (TCF=2-dicyanomethylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran) and the electron-rich heterocyclic π-bridges thiophene and furan dramatically increases the Lewis acidity of new donor-π-acceptor-type arylboronate esters and enables a colorimetric turn-on response induced by the interaction with fluoride ions and weaker Lewis bases, such as pyridine.
- Oehlke, Alexander,Auer, Alexander A.,Schreiter, Katja,Friebe, Nadine,Spange, Stefan
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supporting information
p. 17890 - 17896
(2015/12/08)
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- A METHOD OF PRODUCING THE KEY INTERMEDIATE OF LAPATINIB SYNTHESIS
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The present invention relates to a production method of the compound of formula I, consisting in coupling the iodo derivative of formula III with boronic acid derivatives, catalyzed by suitable Pd catalysts in a solvent, wherein the boronic acid derivatives are cyclic boronates of the general formula VII, wherein R1, R2, R3 and R4 is H, or a C1-C4 (un)branched alky and wherein X is either a bond or CR5R6 wherein R5 and R6 is H, or a C1-C4 (un)branched alkyl. Other aspects of the invention are cyclic boronates and use of the compound of formula I.
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Page/Page column 8
(2014/05/07)
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