新型对硅胶稳定的磺酸硼酸酯，并且Suzuki-Miyaura反应活性更高!

was quenched with H2O, the reaction mixture was extracted thrice with CH2Cl2. The combined organic phase was dried over anhydrous MgSO4 and the solvent was removed under reduced pressure. The crude product was purified by flash column chromatography on silica gel (a mixture of hexane and EtOAc) to afford aryl boronic acid 3,4-diethylhexane-3,4-diol ester, ArB(Epin) 2.

General Procedure II: An oven-dried flask with a magnetic stir bar equipped with an inlet adapter with three-way stopcock was evacuated and back-filled with nitrogen. Aryl halide 3 (1.0 equiv) was charged in the flask and evacuated and back-filled with nitrogen. Anhydrous THF (0.10 M) was added to the flask via a syringe and cooled to –78 °C. 2.7 M n-BuLi in hexane [or 1.0 M i-PrMgCl·LiCl in THF or 1.6 M t-BuLi in pentane] (1.2 equiv) was added to the mixture at –78 °C via a syringe and the mixture was stirred for 1 h. After B(OMe)3 (2.0 equiv) was added to reaction mixture, the reaction mixture was allowed to warm up to room temperature, and stirred 3 h. A saturated solution of NH4Cl was added to the mixture, and the mixture was extracted thrice with EtOAc. The combined organic phase was washed with brine. The organic phase was dried over MgSO4, and the solvent was removed under reduced pressure. The flask was charged with 3,4-diethylhexane-3,4-diol, Epin (1.0 equiv) in CH2Cl2 (10 mL, 0.10 M), and stirred at room temperature. The mixture was evaporated under reduced pressure. The residue was purified by column chromatography on silica gel (a mixture of hexane and EtOAc) to afford aryl boronic acid 3,4-diethylhexane-3,4-diol ester, ArB(Epin) 2.

An oven-dried Schlenk flask was charged with PdCl2(dppp)·CH2Cl2 (2.9 mg, 5.0 mol%), KOAc (29 mg, 0.30 mmol), B2(Epin)2 [1] (55 mg, 0.15 mmol) and a magnetic stirrer bar. The flask was equipped with a rubber septum and evacuated and back-filled with argon (this process was repeated three times). After 1-(4-bromophenyl)ethan-1-one (3g) (20 mg, 0.10 mmol) in anhydrous DMSO S-14 (1.0 mL, 0.10 M) was added via a syringe, the septum was replaced with a Teflon screw cap under a flow of argon, and the cap was tightly closed. The mixture was stirred for 2 h at 80 °C. After cooling to room temperature, the mixture was filtrated through a short pad of celite. The filtrate was evaporated under reduced pressure. The residue was purified by column chromatography on silica gel (hexane/EtOAc = 95:5) to afford the titled compound 2s as a colorless oil (30 mg, 99%).

简要

一、 Aryl Boronic Esters Are Stable on Silica Gel and Reactive under Suzuki–Miyaura Coupling Conditions; Org. Lett. 2022, 24, 19, 3510–3514.

二、 Analysis of Past and Present Synthetic Methodologies on Medicinal Chemistry: Where He All the New Reactions Gone? J. Med. Chem. 2016, 59, 4443−4458.

。

江中初元公司
眼部整容
宝宝积食
类风湿病吃什么药好
术后吃什么好
老是咳嗽怎么办才能止咳
怎么补充眼部营养让视力变好
视疲劳滴哪个滴眼液好用
牙痛最有效的止痛方法
恶心呕吐