Highly Efficient and Versatile Synthesis of Polyarylfluorenes via Pd-Catalyzed C−H Bond Activation
摘要:
A facile protocol for the Pd-catalyzed preparative synthesis of fluorene derivatives has been developed. While a wide range of fluorenes; were easily obtained with high efficiency and selectivity under mild conditions, excellent functional group tolerance was also demonstrated. On the basis of Hammett and KIE studies, the present reaction is proposed to proceed via a base-assisted deprotonative metalation pathway.
The rates of solvolysis of twenty-two m- and p-substituted α-methylbenzyl chlorides were determined in 80% aqueous acetone. The relative rates at 45 °C are not correlated linearly with σ0 or σ. The use of Brown’s σ+ improves the fit but the resulting correlation is still concave. An excellent correlation, logk⁄k0=−4.950(σ0+1.147Δ\barσR+), was obtained by applying the LArSR equation. The r value 1.15
A molecular iodine-mediated formal [2+1+1+1] cycloaddition for the efficient synthesis of pyrrolo[2,1-a]isoquinolines from acetophenones, 1,2,3,4-tetrahydroisoquinoline (THIQ) and DMSO has been developed. Mechanistic studies revealed that DMSO served as the methylene source, and this novel protocol involves intermolecular cycloaddition of two in situ generated intermediates that enable efficient formation
分子碘介导的正式[2 + 1 + 1 + 1]环加成反应可从苯乙酮,1,2,3,4-四氢异喹啉(THIQ)和DMSO有效合成吡咯并[ 2,1- a ]异喹啉。机理研究表明,DMSO是亚甲基的来源,该新颖的方法涉及分子间环加成两个原位生成的中间体,这些中间体能够通过多个连续的C–H功能化有效地形成一个C–N键和三个C–C键。
One-Pot, Regioselective Synthesis of Homopropargyl Alcohols using Propargyl Bromide and Carbonyl Compound by the Mg-mediated Reaction under Solvent-free Conditions
in organic synthesis is the most important goal in “Green” chemistry. We report a simple, efficient and facile method for the addition of progargyl bromide to carbonyl compounds using Mg metal as a mediator undersolvent-freeconditions which could regioselectively generate homopropargyl alcohols efficiently in good to excellent yields. The procedure has advantages such as short reaction time, operationally
A copper‐catalyzedsite‐selective C5‐dicarbonylation reaction of anthranils has been developed for synthesis of 1,2‐dicarbonyl compounds using methyl ketone as a commercially available carbonylation reagent. This process represents the first example to implement the C5‐dicarbonylation of anthranils, which involves an oxidative Csp3‐H/Csp2‐H cross‐coupling reaction along with thermolytic N−O bond cleavage
已经开发了一种铜催化的蒽的位点C5-二羰基化反应,用于使用甲基酮作为市售的羰基化试剂来合成1,2-二羰基化合物。该过程代表了第一个实现蒽的C5-二羰基化的例子,该过程涉及氧化的C sp 3 -H / C sp 2 -H交叉偶联反应以及热解性N-O键的裂解。
B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>-Catalyzed Asymmetric Reductive Amination of Ketones with Ammonia Borane
first example of metal-free B(C6F5)3-catalyzed asymmetric reduction amination of ketones with chiral α-methylbenzylamine (α-MBA) using ammonia borane as the reductant is reported. This one-pot method has a broad substrate scope and provides various chiralamines in 81–95% yield with 80–99% de. This protocol was further applied in the total synthesis of cinacalcet.
报道了使用氨硼烷作为还原剂,用手性α-甲基苄胺(α-MBA)进行的无金属的B(C 6 F 5)3催化的酮的不对称还原胺化的第一个实例。这种一锅法具有广泛的底物范围,并以81-95%的收率和80-99%的de提供了各种手性胺。该方案进一步应用于西那卡塞的全合成中。