Environmentally friendly homocoupling reaction of functionalized potassium aryl trifluoroborates salts in aqueous media
摘要:
The homocoupling reaction between potassium aryl trifluoroborates containing different functionalities promoted by a catalytic amount of Pd(OAc)(2) is described. The methodology uses water as a solvent under aerobic conditions to give the corresponding biaryl compounds in good yields. (C) 2011 Elsevier Ltd. All rights reserved.
<sup>1</sup>
H, <sup>13</sup>
C, <sup>19</sup>
F and <sup>11</sup>
B NMR spectral reference data of some potassium organotrifluoroborates
作者:Roberta A. Oliveira、Ricardo O. Silva、Gary A. Molander、Paulo H. Menezes
DOI:10.1002/mrc.2467
日期:2009.10
Complete (1)H, (13)C, (19)F and (11)BNMRspectraldata for 28 potassiumorganotrifluoroborates are described. The resonance for the carbon bearing the boron atom is described for most of the studied compounds. A modified (11)BNMR pulse sequence was used and better resolution was observed allowing the observation of (11)B-(19)F coupling constants for some of the studied compounds.
Replacement of the bryostatin A- and B-pyran rings with phenyl rings leads to loss of high affinity binding with PKC
作者:Mark E. Petersen、Noemi Kedei、Nancy E. Lewin、Peter M. Blumberg、Gary E. Keck
DOI:10.1016/j.tetlet.2016.09.040
日期:2016.10
We describe a convergent synthesis of a bryostatin analogue in which the natural A- and B-ring pyrans have been replaced by phenyl rings. The new analogueexhibited PMA like behavior in cell assays, but failed to maintain highaffinitybinding for PKC, despite retaining an unaltered C-ring 'binding domain'.
Pd-Catalyzed C-3 functionalization of indolizines via C–H bond cleavage
作者:Baoli Zhao
DOI:10.1039/c2ob25643f
日期:——
New transition metal-catalyzed methods for the arylation of indolizines by the direct cleavage of CâH bonds have been developed. A wide range of aryltrifluoroborate salts react with indolizines in the presence of Pd(OAc)2 catalyst and AgOAc oxidant to give the arylated indolizines in high yields. Both electron-donating and electron-withdrawing groups perform smoothly while bromide and chlorine substituents are tolerated. In addition, the indolizines display similar reactivities in the Pd-catalyzed reaction with 3-phenylpropiolic acid to afford the corresponding C-3 alkynylated indolizines. These methods allow the direct functionalization of indolizines in one step.
Efficient Hydrolysis of Organotrifluoroborates via Silica Gel and Water
作者:Gary A. Molander、Livia N. Cavalcanti、Belgin Canturk、Po-Shen Pan、Lauren E. Kennedy
DOI:10.1021/jo901441u
日期:2009.10.2
and efficient method for the hydrolysis of organotrifluoroborates to unveil boronic acids using silicagel and H2O was developed. This method proved to be tolerant of a broad range of aryl-, heteroaryl-, alkenyl-, and alkyltrifluoroborates as well as structurally diverse aminomethylated organotrifluoroborates. As anticipated, electron-rich substrates provided the corresponding boronic acids more readily
开发了一种使用硅胶和 H 2 O水解有机三氟硼酸盐以揭示硼酸的通用、温和且有效的方法。事实证明,该方法可以耐受各种芳基-、杂芳基-、烯基-和烷基三氟硼酸盐以及结构多样的氨甲基化有机三氟硼酸盐。正如预期的那样,由于共振稳定的二氟硼烷中间体,富电子底物比缺电子底物更容易提供相应的硼酸。开发的方法进一步扩展用于将有机三氟硼酸盐转化为相应的硼酸酯。
Palladium-Catalyzed Borylation of Aryl and Heteroaryl Halides Utilizing Tetrakis(dimethylamino)diboron: One Step Greener
作者:Gary A. Molander、Sarah L. J. Trice、Steven M. Kennedy
DOI:10.1021/ol302124j
日期:2012.9.21
borylating agent, tetrakis(dimethylamino)diboron [(Me2N)2B–B(NMe2)2], is reported. The method is complementary to the previously reported method utilizing bis-boronic acid (BBA) in that certain substrates perform better under one set of optimized reaction conditions than the other. Because tetrakis(dimethylamino)diboron is the synthetic precursor to both BBA and bis(pinacolato)diboron (B2Pin2), the new