Asymmetric Radical Cyclopropanation of Alkenes with In Situ-Generated Donor-Substituted Diazo Reagents via Co(II)-Based Metalloradical Catalysis
作者:Yong Wang、Xin Wen、Xin Cui、Lukasz Wojtas、X. Peter Zhang
DOI:10.1021/jacs.6b11336
日期:2017.1.25
Donor-substituted diazo reagents, generated in situ from sulfonyl hydrazones in the presence of base, can serve as suitable radical precursors for Co(II)-based metalloradicalcatalysis (MRC). The cobalt(II) complex of D2-symmetric chiralporphyrin [Co(3,5-DitBu-Xu(2'-Naph)Phyrin)] is an efficient metalloradicalcatalyst that is capable of activating different N-arylsulfonyl hydrazones for asymmetric radical
Synthesis of 1,2,3,4‐Tetrahydroisoquinolines via Palladium‐Catalyzed Cyclization of
<i>N</i>
‐Tosylhydrazones with
<i>ortho</i>
‐Bromophenethyl Tosylamides
A Pd-catalyzed synthesis of 1,2,3,4-tetrahydroisoquinoline (THIQ) via cyclization of ortho-bromophenethyl tosylamides with aryl N-tosylhydrazones in the presence of base was developed. The reaction is believed to proceed via the oxidative addition of palladium with ortho-bromophenethyl tosylamides, followed by carbene insertion and cyclization. The carbene species were generated in-situ from the aryl
开发了一种 Pd 催化合成 1,2,3,4-四氢异喹啉 (THIQ),方法是在碱存在下邻溴苯乙基甲苯磺酰胺与芳基N-甲苯磺酰腙环化。据信该反应是通过钯与邻-溴苯乙基甲苯磺酰胺的氧化加成反应进行的,然后是卡宾插入和环化。卡宾物种由芳基N-甲苯磺酰腙和 KO t Bu 原位生成。
Palladium/GF-Phos-catalyzed asymmetric carbenylative amination to access chiral pyrrolidines and piperidines
作者:Yue Sun、Chun Ma、Zhiming Li、Junliang Zhang
DOI:10.1039/d2sc03999k
日期:——
but the development of catalyticenantioselective versions still poses considerable challenges and only very limited examples have been reported. We herein report an asymmetric palladium/GF-Phos-catalyzed carbenylative amination reaction of N-tosylhydrazones and (E)-vinyl iodides pendent with amine, which allows facile access to a range of chiral pyrrolidines and piperidines in good yields (45–93%)
N-甲苯磺酰腙的交叉偶联已成为构建结构多样化分子的有效方法,但催化对映选择性版本的开发仍然面临相当大的挑战,并且仅报道了非常有限的例子。我们在此报告了一种不对称钯/GF-Phos催化的N-甲苯磺酰腙和( E )-乙烯基碘化物与胺悬垂的羧基胺化反应,该反应可以轻松获得一系列手性吡咯烷和哌啶,产率良好(45-93%) ) 高达 96.5: 3.5 er 。此外,条件温和、底物范围广泛、制备规模化以及天然产物(−)-norruspoline的高效合成是该方法的实用特点。
Synthesis and computational studies of potent antimicrobial and anticancer indolone scaffolds with spiro cyclopropyl moiety as a novel design element
An efficient one‐pot N‐alkylation of benzimidazole and benzotriazole from carbonyl compounds and tosylhydrazide has been accomplished via copper powder‐catalyzed N—H bond insertion affording N‐alkylated products in good yields. The reaction can tolerate a wide range of carbonyl compounds, such as aryl, alkyl, heterocyclic and α,β‐unsaturated ketones, and aldehydes.