Synergistic Effect of a Bis(proazaphosphatrane) in Mild Palladium-Catalyzed Direct α-Arylations of Nitriles with Aryl Chlorides
作者:So Han Kim、Wonseok Jang、Min Kim、John G. Verkade、Youngjo Kim
DOI:10.1002/ejoc.201402466
日期:2014.9
The effect of a bis(proazaphosphatrane) ligand on the palladium-catalyzed direct α-arylation of nitriles with various arylchlorides under mild conditions is reported. Comparisons of the catalytic properties of this ligand with those of three related mono(proazaphosphatrane)s under the same reaction conditions revealed that bis(proazaphosphatrane) displayed a synergistically enhanced activity. In the
P(<i>i</i>-BuNCH<sub>2</sub>CH<sub>2</sub>)<sub>3</sub>N: An Efficient Ligand for the Direct α-Arylation of Nitriles with Aryl Bromides
作者:Jingsong You、John G. Verkade
DOI:10.1021/jo034779h
日期:2003.10.1
A new catalyst system for the synthesis of alpha-aryl-substituted nitriles is reported. The bicyclic triaminophosphine P(i-BuNCH2CH2)(3)N (1b) serves as an efficient and versatile ligand for the palladium-catalyzed direct alpha-arylation of nitriles with aryl bromides. Using ligand 1b, ethyl cyanoacetate and primary as well as secondary nitriles are efficiently coupled with a wide variety of aryl bromides possessing electron-rich, electron-poor, electron-neutral, and sterically hindered groups.
Arylation of diethyl malonate and ethyl cyanoacetate catalyzed by palladium/di-tert-butylneopentylphosphine
作者:Jeffrey G. Semmes、Stephanie L. Bevans、C. Haddon Mullins、Kevin H. Shaughnessy
DOI:10.1016/j.tetlet.2015.01.072
日期:2015.6
α-Arylated carbonyl derivatives are important structural motifs in many natural products and pharmaceutically active compounds. Although arylation of simple monocarbonyl compounds is a well-established methodology, metal-catalyzed arylation of β-dicarbonyl derivatives is significantly more challenging. The ability of β-dicarbonyl anions to bind to palladium in a κ2-O,O mode, rather than the κ1-C-bound
在许多天然产物和药物活性化合物中,α-芳基化羰基衍生物是重要的结构基序。尽管简单的单羰基化合物的芳基化是一种公认的方法,但金属催化的β-二羰基衍生物的芳基化更具挑战性。β二羰基的阴离子结合至钯在κ的能力2 - ø,ö模式,而不是κ 1 - c ^结合的模式键形成所需的,经常导致催化剂体系的失活。烯醇盐的C-结合形式可通过使用空间需求的配体来促进。在此,我们报告中指出,空间要求的二叔丁基丁基新戊基膦(DTBNpP)配体与Pd(dba)2结合为芳基溴化物和氯化物与丙二酸二乙酯的偶联提供了有效的催化剂。Pd / DTBNpP系统还催化芳基溴化物与氰基乙酸乙酯的偶联。
A rational design strategy of radical-type mechanophores with thermal tolerance
. A combined experimental and theoretical analysis revealed that the high thermal tolerance of these RMs is related to the radical-stabilization energy (RSE) as well as the Hammett and modified Swain–Lupton constants at the para-position (σp). The trend of the RSE values is in good agreement with the experimentally evaluated thermal tolerance of a series of mechanoresponsive RMs based on the bisarylcyanoacetate