Preparation of 5-Acyl- and 5-Aryl-Substituted 1-(Benzyloxy)pyrazoles via Directed Ortho-Lithiation/Transmetalation and Palladium Catalyzed Cross-Coupling
Preparation of 5-Acyl- and 5-Aryl-Substituted 1-(Benzyloxy)pyrazoles via Directed Ortho-Lithiation/Transmetalation and Palladium Catalyzed Cross-Coupling
复制标题
通过直接邻位锂化/金属转移和钯催化交叉偶联制备 5-酰基和 5-芳基取代的 1-(苄氧基)吡唑
DOI：
10.1055/s-1998-2201
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
P. Vedsø
中科院分区：
文献类型：
--
作者：
J. Kristensen;M. Begtrup;P. Vedsø
钯（0）催化的1-（苄氧基）吡唑-5-基卤化锌3a、B（通过1-（苄氧基）-5-锂吡唑（2）的金属转移反应制备）与酰氯的交叉偶联以高产率产生5-酰基-1-（苄氧基）吡唑4a-d。吡唑-5-基卤化锌与氨基-、羟基-、甲氧基-、氟-、硝基-或甲酰基-取代的碘苯的类似偶联得到相应的5-芳基-1-（苄氧基）吡唑5a-f，而与碘噻吩、碘吡唑或溴吡啶的偶联得到相应的1-（苄氧基）-5-杂芳基吡唑6a-c。
: Palladium(0) catalyzed cross-coupling of 1-(benzyl-oxy)pyrazol-5-ylzinc halides 3a,b , prepared by transmetalation of 1-(benzyloxy)-5-lithiopyrazole (2) , with acyl chlorides produced 5- acyl-1-(benzyloxy)pyrazoles 4a–d in high yields. Similar coupling of the pyrazol-5-ylzinc halide with amino-, hydroxy-, methoxy-, fluoro-, nitro-, or formyl-substituted iodobenzene gave the corresponding 5-aryl-1-(benzyloxy)pyrazoles 5a–f , while coupling with iodothiophene, iodopyrazole or bromopyridine provided the corresponding 1-(benzyloxy)-5-heteroarylpyrazoles 6a–c .