PtI<sub>2</sub>-catalyzed cyclization of 3-acyloxy-1,5-enynes with the elimination of HOAc and a benzyl shift: synthesis of unsymmetrical m-terphenyls
作者:Kaimeng Huang、Xiaona Ke、Hongkai Wang、Junying Wang、Chenchen Zhou、Xiufang Xu、Lingyan Liu、Jing Li
DOI:10.1039/c4ob02336f
日期:——
A new cyclization of 1,5-enyne was developed to synthesize the m-terphenyls via the elimination of HOAc and a benzyl shift.
开发了一种新的1,5-炔烃环化反应,通过消除HOAc和苯甲基转移来合成m-联苯。
Pd(ii) complexes of N,S-heterocyclic carbenes with pendant and coordinated allyl function and their Suzuki coupling activities
作者:Swee Kuan Yen、Lip Lin Koh、Han Vinh Huynh、T. S. Andy Hor
DOI:10.1039/b706968e
日期:——
3-(2-Propenyl)benzothiazolium bromide (A) provides a direct and simple entry to Pd(II) complexes with N,S-heterocyclic carbene (NSHC) ligands functionalized with an allyl pendant with hemilabile potential. Addition of salt A to Pd(OAc)2 eliminates HOAc and affords the bis(carbene) complexes cis-[PdBr2(NHSC)2] (cis-1, NSHC = 3-(2-propenyl)benzothiazolin-2-ylidene) and trans-[PdBr2(NHSC)2] (trans-1) along with the monocarbene complexes [PdBr2(NSHC)] (2) and trans-[PdBr2(benzothiazole-κN)(NSHC)] (3) as minor side products. Salt-metathesis of cis-1 with AgO2CCF3 yields the mixed dicarboxylato-bis(carbene) complex cis-[Pd(O2CCF3)2(NSHC)2] (4). Complexes cis-1, trans-1 and 4 were characterized by multinuclear NMR spectroscopies, ESI mass spectrometry and elemental analysis. The molecular structures of complexes cis-1, 2 and 3 have been determined by X-ray single crystal diffraction. Complexes cis-1 and 4 as well as an in situ mixture of Pd(OAc)2 and salt A are active toward Suzuki–Miyaura coupling of aryl bromides and activated aryl chlorides giving good conversions.
Direct CâH bond arylation of simple arenes with aryltin reagents has been successfully catalysed by PdCl2 in the presence of CuCl2. CuCl2 proved to be an activator for a palladium intermediate as well as an oxidant.
A General Palladium-Catalyzed Hiyama Cross-Coupling Reaction of Aryl and Heteroaryl Chlorides
作者:On Ying Yuen、Chau Ming So、Ho Wing Man、Fuk Yee Kwong
DOI:10.1002/chem.201600420
日期:2016.5.4
A general palladium‐catalyzed Hiyama cross‐coupling reaction of aryl and heteroaryl chlorides with aryl and heteroaryl trialkoxysilanes by a Pd(OAc)2/L2 catalytic system is presented. A newly developed water addition protocol can dramatically improve the product yields. The conjugation of the Pd/L2 system and the water addition protocol can efficiently catalyze a broad range of electron‐rich, ‐neutral
Development of Structurally Diverse N-Heterocyclic Carbene Ligands<i>via</i>Palladium-Copper-Catalyzed Decarboxylative Arylation of Pyrazolo[1,5-<i>a</i>]pyridine-3-carboxylic Acid
作者:Khyarul Alam、Seong Min Kim、Do Joong Kim、Jin Kyoon Park
DOI:10.1002/adsc.201600480
日期:2016.8.18
pyrazolo[1,5‐a]pyridines, has been prepared using palladium‐copper‐catalyzed decarboxylative arylation of pyrazolo[1,5‐a]pyridine‐3‐carboxylic acid. Air‐stable palladium and rhodium complexes of these ligands have been synthesized via mild transmetallation of Ag‐Pyrpy‐NHC. The structural properties of Rh(Pyrpy‐NHC)(COD)Cl complexes were determined via X‐ray analysis. The measurement of the CO stretching frequencies