Ruthenium Catalyzed C−H Amidation and Carbocyclization using Isocyanates: An Access to Amidated 2‐phenylphthalazine‐1,4‐diones and Indazolo[1,2‐
<i>b</i>
]phthalazine‐triones
作者:Pidiyara Karishma、Alisha Gogia、Sanjay K. Mandal、Rajeev Sakhuja
DOI:10.1002/adsc.202001146
日期:2021.2.2
A direct carbocyclization of 2‐aryl‐2,3‐dihydrophthalazine‐1,4‐diones is achieved using isocyanates as carbonyl source via Ru(II)‐catalyzed sequential ortho‐amidation followed by intramolecular nucleophilic substitution, delivering substituted indazolo[1,2‐b]phthalazine‐triones in good‐to‐excellent yields. For ortho‐substituted 2‐aryl‐2,3‐dihydrophthalazine‐1,4‐diones, the corresponding amidated products
使用异氰酸酯作为羰基来源,通过Ru(II)催化的顺序邻位酰胺化反应,然后进行分子内亲核取代,将取代的吲唑并[ 2,2-]-2-芳基-2,3-二氢酞嗪-1,4-二酮直接碳环化[1,2] ‐ b ]酞嗪三酮,收率良好。对于邻位取代的2-芳基-2,3-二氢邻苯二甲酸1,4-二酮,还可以通过修改反应参数以高收率分离出相应的酰胺化产物。异氰酸酯作为羰基来源的应用,在两个偶联配偶体上的高官能团耐受性以及合成的熔融和官能化邻苯二氮酮的多种化学转化是这项工作的重点。