Synthesis of aromatic acids via catalysed methyl formate-chloroarene reactions

Chlorobenzene and more generally, chloroarenes, can be converted into aromatic acids via catalytic reaction with aqueous methyl formate under biphasic conditions. The only efficient catalyst is [PdCl₂(PCy₃)₂] (Cy = cyclohexyl). [RU₃(CO)₁₂] and ammonium formate improve yield and selectivity. The mechanism should involve oxidative addition of the C---Cl bond to a zero-valent Pd species followed by CO insertion. The palladium catalyst may also directly activate methyl formate. The procedure is convenient (no solvent, no initial pressurization) and at least as efficient as previously described methods.     

The simple solvent-free synthesis of 1H-quinazoline-2,4-diones using supercritical carbon dioxide and catalytic amount of base

Only supercritical carbon dioxide (scCO₂) as a reactant and a solvent, and catalytic amount of base (DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), DBN (1,5-diazabicyclo[4.3.0]non-5-ene), Dabco^® (1,4-diazabicyclo[2.2.2]octane), and triethylamine) afforded 1H-quinazoline-2,4-diones in good to excellent yields from 2-aminobenzonitriles. 6,7-Dimethoxy-1H-quinazoline-2,4-dione, which is a key intermediate of medicines (Prazosin, Bunazosin, and Doxazosin) was synthesized successfully in a 97% yield, using 0.1 equiv of DBU under scCO₂ (10 MPa) at 80 °C.     

三（2—吡啶甲基）甲烷为配体的双金属配合物的制备及其催化性能研究

报道了一种新的以三（２－吡啶甲基）甲烷为配体，以铑为主催化活性中心，并辅以其它金属为辅助催化的双金属配合物该配合物在相对温和的条件下，可迅速催化甲醇羰基化为醋酸，及醋酸甲酯羰基化为醋酐。实验结果证明，第二种金属的引入提高了配合物的催化活性，这种催化活性的提高因第二种金属的不同而有所差异。另外，根据配体的结构阐述了其对羰基化反应的作用机理。     

配合Pd催化剂薄荷醇与异丁烯羰基合成Validol

用PdCL2(PPh3)2/PPh3/P-CH3C6H4SO3H复合催化体系,在间歇高压釡中,以二甲苯为溶剂,在一定的反应温度、CO/H2压力和薄荷醇与异丁烯浓度下,研究了主催化剂浓度和各种助催化剂的配比对薄荷醇转化率和反应速度的影响.在适宜的催化体系和反应体系中,进行了反应物的转化率、Validol的选择性和收率与反应时间关系实验.对98%以上Validol产物进行了FT-TR、MS、13C NMR和1H NMR鉴别.最后,完成了反应温度、CO压力和薄荷醇、异丁烯浓度对羰基合成Validol反应速度的影响实验,提出了该反应的反应机理和催化循环过程.     

Design and synthesis of novel 1,4-benzodiazepine surrogates as potential CCKA and CCKB antagonists via palladium-catalyzed three-component cascade reactions

Structurally diverse novel 1,4-benzodiazepine analogues related to selective CCKA antagonist MK-329, and CCKB antagonists L-365,260 and YM022 are prepared via palladium-catalyzed three component domino reactions involving allenylation-carbonylation-anion capture in one-pot cascade protocol in good to excellent yields.     

Efficient access to (1H)-isoindolin-1-one-3-carboxylic acid derivatives by orthopalladation and carbonylation of methyl arylglycinate substrates

The orthopalladation of methyl arylglycinate derivatives has been studied. The reaction proceeds efficiently for different electron-withdrawing and electron-releasing substituents at the aryl ring. The carbonylation of the orthopalladated complexes affords, in a single step, substituted (1H)-isoindolin-1-one-3-carboxylates. These compounds constitute valuable synthetic intermediates and can be transformed diastereoselectively into octahydroisoindole-1-carboxylic acid derivatives, an important scaffold in the synthesis of many biologically active compounds.     

Manganese-catalyzed ring-opening carbonylation of cyclobutanol derivatives

Herein, we report a manganese-catalyzed ring-opening carbonylation of cyclobutanol derivatives through cyclic CC bond cleavage. The reaction happens via a radical-mediated pathway to selectively generate 1,5-ketoesters. A variety of substrates with substituents on the aromatic ring reacted with linear alcohols of different chain lengths. Obtained aliphatic esters are very attractive since they are usually difficult to access.     

Carbonylation studies of Pd-methyl complexes modified with 1,4-Cs-symmetrical diphosphine ligands

Neutral palladium methyl chloride 2a-d [PdCH₃(PˆP′)Cl] and cationic palladium methyl acetonitrile mono-triflate 3a-d [PdCH₃(PˆP′)(CH₃CN)](CF₃SO₃) complexes were synthesized and fully characterized (PˆP′ = 1a-d). All the neutral and cationic complexes containing a C_s-symmetric diphosphine exist in solution as a mixture of geometric isomers. The carbonylation at atmospheric pressure of the neutral and cationic complexes revealed that migratory insertion of carbon monoxide is not stereospecific in these systems. The neutral and cationic acyl complexes were formed in situ as mixtures of stereoisomers, which were characterized by means of NMR spectroscopy.The crystal structures of [Pd(1a)Cl]₂(OTf)₂ and 2d are described.     

过渡金属助剂对催化甲醇羰基化反应的影响

过渡金属助剂对催化甲醇羰基化反应的影响①彭文庆袁国卿②（中国科学院化学研究所，北京１０００８０）关键词过渡金属助剂铑络合物催化剂羰基化甲醇过渡金属催化剂已广泛地应用于加氢、脱氢、羰基化等反应，并显示了优良的催化活性与选择性，而且过渡金属作为助催化剂在...