Palladium-Catalyzed Esterification of Carboxylic Acids with Aryl Iodides
作者:Hiroyuki Kitano、Hideto Ito、Kenichiro Itami
DOI:10.1021/acs.orglett.8b00775
日期:2018.4.20
The first palladium-catalyzed esterification of carboxylicacids with aryl iodides is described. A palladium-based catalytic system consisting of IBnF (1,3-bis((pentafluorophenyl)methyl)imidazole-2-ylidene) ligand was found to significantly accelerate the aryl–O bond-forming esterification reaction. A series of aryl iodides and carboxylicacids undergoes a palladium-catalyzed coupling reaction to provide
Rhodium-catalyzed borylation reactions of aryl and alkenyl pivalates, using a diboron reagent, via the cleavage of carbon–oxygen bonds have been developed. The inert nature of the pivalate moiety enables relatively complex aryl boronates to be synthesized via the tandem cross-coupling of carbon–halogen and carbon–oxygen bonds.
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。
Cyanation of Phenol Derivatives with Aminoacetonitriles by Nickel Catalysis
nickel-catalyzed cyanation of phenol derivatives with metal-free cyanating agents, aminoacetonitriles, is described. A nickel-based catalytic system consisting of a unique diphosphine ligand such as dcype or dcypt enables the cyanation of versatile phenol derivatives such as aryl carbamates and aryl pivalates. The use of aminoacetonitriles as a cyanating agent leads to an environmentally and easy-to-use method
substrates represents a major challenge of the present cross‐coupling methodology. The nickel‐catalyzed Kumada cross‐ coupling of tertiary alkyl Grignard reagents with arylbromides allows this difficult reaction with numerous different substrates. Optimal results were obtained using sterically demanding, bifunctional N‐heterocyclic carbene ligands.