Nickel-Catalyzed Stille Cross Coupling of C-O Electrophiles.
Nickel-Catalyzed Stille Cross Coupling of C-O Electrophiles.
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DOI：
10.1021/acscatal.9b00744
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发表时间：
2019-03
期刊：
影响因子：
12.9
通讯作者：
John E. A. Russell;Emily D. Entz;I. Joyce;Sharon R. Neufeldt
中科院分区：
文献类型：
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作者：
John E. A. Russell;Emily D. Entz;I. Joyce;Sharon R. Neufeldt
芳基氨基甲酸酯、甲酰氨基甲酸酯和甲酰基氨基甲酸酯在相对畅通的烷基膦配体和KF存在下与不同的有机硅烷进行高效的镍催化交叉偶联。偶联是有价值的困难的键结构，如芳基-杂芳基，芳基-烯基，芳基-炔基，使用非三氟化苯酚衍生物。实验和计算研究的结合暗示了涉及8中心循环过渡态的金属转化的不寻常机制。由于有机硅烷在Ni(II)-氯中间体上的金属转化缓慢，该反应被氯源抑制。这些研究有助于解释为什么以前的努力实现镍催化斯蒂尔偶联苯酚衍生物是不成功的。
Aryl sulfamates, tosylates, and mesylates undergo efficient Ni-catalyzed cross coupling with diverse organostannanes in the presence of relatively unhindered alkylphosphine ligands and KF. The coupling is valuable for difficult bond constructions, such as aryl- heteroaryl, aryl-alkenyl, and aryl-alkynyl, using non-triflate phenol derivatives. A combination of experimental and computational studies implicate an unusual mechanism for transmetalation involving an 8-centered cyclic transition state. This reaction is inhibited by chloride sources due to slow transmetalation of organostannanes at a Ni(II)-chloride intermediate. These studies help to explain why prior efforts to achieve Ni-catalyzed Stille coupling of phenol derivatives were unsuccessful.