for a range of aryl halide and boronate coupling partners. Notably, aryl chlorides are viable coupling partners even under relatively mild conditions at short reaction times (e.g., 1 h at 60 °C). One of the best catalysts described here exhibits improved turnover frequency for a particularly difficult coupling reaction involving an aryl chloride and a sterically congested boronicester.
已经开发了一系列具有酰胺,尿素和氨基甲酸酯骨架的新型单连接芳基四环复合物,发现它们对Suzuki-Miyaura交叉偶联具有很高的活性。这些Palladacycle预催化剂衍生自简单,廉价的原料,并且对空气和湿气稳定。在测试的那些中最活跃的同类物是基于尿素的palladacycles,它与t Bu 3一起使用。P配体可诱导一系列芳基卤和硼酸酯偶联伙伴的高转化率。值得注意的是,即使在相对温和的条件下,较短的反应时间(例如,在60°C下1 h),芳基氯化物也是可行的偶合伴侣。这里描述的最好的催化剂之一对于特别困难的偶合反应表现出改善的周转频率,所述偶合反应涉及芳基氯和空间拥挤的硼酸酯。
Weak Coordination Promoted Regioselective Oxidative Coupling Reaction for 2,2′-Difunctional Biaryl Synthesis in Hexafluoro-2-propanol
作者:Chao Zhang、Yu Rao
DOI:10.1021/acs.orglett.5b02115
日期:2015.9.18
An unprecedented weak coordination promoted dehydrogenative cross-coupling reaction has been developed by palladium catalysis, which provides a convenient access to a wide range of 2,2′-difunctional biaryls from easily accessible substrates. Both HFIP solvent and oxidants serve as the critical factors in this new reaction. A plausible mechanism involving Pd(II)/Pd(IV) is proposed. The reaction demonstrates
A General Approach towards Catechol and Pyrogallol through Ruthenium‐ and Palladium‐Catalyzed CH Hydroxylation by Weak Coordination
作者:Xinglin Yang、Yonghui Sun、Zhang Chen、Yu Rao
DOI:10.1002/adsc.201300999
日期:2014.5.5
An efficient ruthenium(II)‐ and palladium(II)‐catalyzed CH hydroxylation of aryl carbamates has been developed for the facile synthesis of catechols and pyrogallols. The reaction demonstrates excellent reactivity, regio‐ and chemoselectivity, good functional group compatibility and high yields. The practicality of this method has been proved by a gram‐scale synthesis.
A Rh(III)-catalyzed multiple C–H bond activation/cyclization of phenol derivatives with alkynes was developed. Polyaryl-substituted naphthol derivatives, potentially useful as organic optoelectronic materials, were obtained in moderate to good yields.
Pd(II)-Catalyzed C−H Activation/Aryl−Aryl Coupling of Phenol Esters
作者:Bin Xiao、Yao Fu、Jun Xu、Tian-Jun Gong、Jian-Jun Dai、Jun Yi、Lei Liu
DOI:10.1021/ja909818n
日期:2010.1.20
reactions have been well-known, Pd(II) insertion into C-H bonds promoted by coordination of an oxygen-only group to the palladium remains rather rare. In the present study, the first cyclopalladation complex formed from a simple phenol ester was characterized by X-ray crystallography. A promising protocol for the ortho C-H activation/aryl-aryl coupling of phenol esters that was not sensitive to moisture
尽管含氮基团导向的环钯化反应已广为人知,但通过仅含氧的基团与钯的配位促进 Pd(II) 插入 CH 键的情况仍然相当罕见。在本研究中,第一个由简单苯酚酯形成的环钯化配合物通过 X 射线晶体学表征。然后建立了对水分或空气不敏感的苯酚酯邻位 CH 活化/芳基-芳基偶联的有前途的方案。该反应的效用已被证明可用于合成有用的苯酚衍生物。