Nickel-Catalyzed Cross-Coupling of Potassium Aryl- and Heteroaryltrifluoroborates with Unactivated Alkyl Halides
摘要:
A method for the cross-coupling of alkyl electrophiles with various potassium aryl- and heteroaryltrifluoroborates has been developed. Nearly stoichiometric amounts of organoboron species could be employed to cross-couple a large variety of challenging heteroaryl nucleophiles. Several functional groups were tolerated on both the electrophilic and the nucleophilic partners. Chemoselective reactivity of C(sp(3))-Br bonds in the presence of C(sp(2))-Br bonds was achieved.
α-Phosphonovinyl Arylsulfonates: An Attractive Partner for the Synthesis of α-Substituted Vinylphosphonates through Palladium-Catalyzed Suzuki Reactions
A new and attractive coupling partner for the synthesis of α‐substituted vinylphosphonates through Suzuki reactions has been developed. The developed O‐centered electrophiles couple with various organoboron reagents to give α‐substituted vinylphosphonates in moderate to excellent yields. This protocol features broad substrate scope, mild conditions, and high efficiency.
Synthesis and Applications of α-Trifluoromethylated Alkylboron Compounds
作者:O. Andreea Argintaru、DaWeon Ryu、Ioana Aron、Gary A. Molander
DOI:10.1002/anie.201308036
日期:2013.12.16
RBF3K is a chemist's BFF: A metal‐free synthetic route to unprecedented organoboron compounds bearing an α‐trifluoromethyl substituent, employing a variety of trifluoroborate (RBF3K) starting materials, is reported. These substrates represent the first isolated α‐trifluoromethylated alkylboron building blocks, and these reagents lead to a variety of useful bench‐stable, synthetic intermediates. Pin=pinacol
An efficient and straightforward route to terminal vinyl sulfones via palladium-catalyzed Suzuki reactions of α-bromo ethenylsulfones
作者:Yewen Fang、Meijuan Yuan、Juncong Zhang、Li Zhang、Xiaoping Jin、Ruifeng Li、Jinjian Li
DOI:10.1016/j.tetlet.2016.02.065
日期:2016.3
A general and simple protocol for the synthesis of α-substituted alkenylsulfones has been developed firstly via palladium-catalyzed Suzuki reactions between α-bromo ethenylsulfones and organoborons. Using a catalyst composed of Pd(OAc)2 and SPhos, a variety of aryl, heteroaryl, and alkylboron reagents could efficiently couple with α-bromo ethenylsulfones under mild conditions. Moreover, it has been
Palladium-Catalyzed Suzuki Cross-Coupling of 2-Halo-Deazapurines with Potassium Organotrifluoroborate Salts in the Regioselective Synthesis of Imidazo[4,5-b]pyridine Analogues
作者:Bhaskaran Savitha、Ayyiliath. M. Sajith、M. Nibin Joy、K.K. Abdul Khader、A. Muralidharan、M. Syed Ali Padusha、Yadav D. Bodke
DOI:10.1071/ch15420
日期:——
In this paper, we report the use of potassium organotrifluoroborate salts as nucleophilic organoboron reagents in the Suzuki cross-coupling reactions of 2-halo deazapurines. Regio-isomeric C-2-substituted imidazo[4,5-b]pyridine analogues were synthesized by employing this protocol in good to excellent yields. Whereas aryl and heteroaryl trifluoroborates reacted readily to give the coupled products
在本文中,我们报告了在三卤代脱氮嘌呤的Suzuki交叉偶联反应中有机三氟硼酸钾盐作为亲核有机硼试剂的用途。通过使用该方案以良好至优异的产率合成了区域异构的C-2-取代的咪唑并[4,5- b ]吡啶类似物。芳基和杂芳基三氟硼酸酯容易反应,以高收率得到偶联产物,而三氟硼酸烷基酯则反应性较低。发现乙酸四丁铵的利用在提高交叉偶联过程的反应速率中起重要作用。另外,在硼酸和有机三氟硼酸钾盐之间进行了比较研究。
Electrophilic Aromatic Substitutions of Aryltrifluoroborates with Retention of the BF<sub>3</sub><sup>–</sup> Group: Quantification of the Activating and Directing Effects of the Trifluoroborate Group
contrast to common belief, substitutions at CH positions are often faster than ipso-substitutions of the BF3K group, because BF3K activates the position attached to boron by a factor of 10(3)-10(4) while adjacent CH positions are activated by factors of 10(5)-10(6). Several reactions that have previously been interpreted as ipso-substitutions actually proceed via initial substitution at a vicinal or remote