ADC-Based Palladium Catalysts for Aqueous Suzuki鈥揗iyaura Cross-Coupling Exhibit Greater Activity than the Most Advantageous Catalytic Systems
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- 作者：Mikhail A. Kinzhalov ; Konstantin V. Luzyanin ; Vadim P. Boyarskiy ; Matti Haukka ; Vadim Yu. Kukushkin
- 刊名：Organometallics
- 出版年：2013
- 出版时间：September 23, 2013
- 年：2013
- 卷：32
- 期：18
- 页码：5212-5223
- 全文大小：512K
- 年卷期：v.32,no.18(September 23, 2013)
- ISSN：1520-6041
文摘
The reaction between the equimolar amounts of cis-[PdCl2(CNR1)2] (R1 = cyclohexyl (Cy) (1), tBu (2)) and the carbohydrazides R2CONHNH2 (R2 = Ph (5), 4-ClC6H4 (6), 3-NO2C6H4 (7), 4-NO2C6H4 (8), 4-CH3C6H4 (9), 3,4-(MeO)2C6H3 (10), naphth-1-yl (11), fur-2-yl (12), 4-NO2C6H4CH2 (13), Cy (14), 1-(4-fluorophenyl)-5-oxopyrrolidin-3-yl (15), (pyrrolidin-1-yl)C(O) (16)) proceeds in refluxing CHCl3 for ca. 4 h. A subsequent workup provided the aminocarbene species cis-[PdCl2{C(NHNHC(O)R2)鈺怤(H)R1}(CNR1)] (18鈥?b>33) in good to excellent (80鈥?5%) isolated yields. The coupling of equimolar amounts of cis-[PdCl2(CNR1)2] (R1 = Cy (1), tBu (2), 2,6-Me2C6H3 (Xyl) (3), 2-Cl-6-MeC6H3 (4)) and PhSO2NHNH2 (17) occurs similarly and affords the aminocarbenes cis-[PdCl2{C(NHNHS(O)2Ph)鈺怤(H)R1}(CNR1)] (34鈥?b>37; 60鈥?0%). Complexes 18鈥?b>37 were characterized by elemental analyses (C, H, N), ESI+-MS, IR, and 1D (1H, 13C{1H}) and 2D (1H,1H-COSY, 1H,13C-HMQC/1H,13C-HSQC, 1H,13C-HMBC) NMR spectroscopy, as well as by X-ray diffraction for three species (34, 37, and 38).
The catalytic properties of 18鈥?b>37 in Suzuki鈥揗iyaura cross-coupling in aqueous medium were evaluated, and 18鈥?b>37 showed remarkable activity (0.001鈥?.01 mol % catalyst loading). The scope of the catalytic process covers sterically unhindered and sterically demanding aryl bromides and aryl iodides bearing donor and/or acceptor substituents and activated aryl chlorides. All organohalides reacted with a range of arylboronic acids at 80 掳C within 2 h (100 掳C and 3 h for the chlorides), providing target diaryls in yields up to 99% and with maximum TONs of 9.9 脳 103 (for aryl iodides), 4.7 脳 104 (for aryl bromides), and 9.2 脳 103 (for aryl chlorides).
The catalytic properties of 18鈥?b>37 in Suzuki鈥揗iyaura cross-coupling in aqueous medium were evaluated, and 18鈥?b>37 showed remarkable activity (0.001鈥?.01 mol % catalyst loading). The scope of the catalytic process covers sterically unhindered and sterically demanding aryl bromides and aryl iodides bearing donor and/or acceptor substituents and activated aryl chlorides. All organohalides reacted with a range of arylboronic acids at 80 掳C within 2 h (100 掳C and 3 h for the chlorides), providing target diaryls in yields up to 99% and with maximum TONs of 9.9 脳 103 (for aryl iodides), 4.7 脳 104 (for aryl bromides), and 9.2 脳 103 (for aryl chlorides).