Sulfur-controlled and rhodium-catalyzed formal (3 + 3) transannulation of thioacyl carbenes with alk-2-enals and mechanistic insights
作者:Qiuyue Wu、Ziyang Dong、Jiaxi Xu、Zhanhui Yang
DOI:10.1039/d1ob00116g
日期:——
A rhodium-catalyzed denitrogenative formal (3 + 3) transannulation of 1,2,3-thiadiazoles with alk-2-enals is achieved and a mechanistic investigation is performed, with an inverse KIE of 0.49 obtained.
Selective Synthesis of Indazolo[2,3‐
<i>a</i>
]quinolines via Rh(III)‐Catalyzed Oxidant‐Free [4+2] or [5+1] Annulation of 2‐Aryl‐2
<i>H</i>
‐indazoles with
<i>α</i>
‐Diazo Carbonyl Compounds
作者:Shenghai Guo、Lincong Sun、Xuzhuo Li、Xinying Zhang、Xuesen Fan
DOI:10.1002/adsc.201901422
日期:2020.2.21
A selective synthesis of 5,6‐disubstituted and 5‐substituted indazolo[2,3‐a]quinolines through a Rh(III)‐catalyzed oxidant‐free annulation of 2‐aryl‐2H‐indazoles with α‐diazo carbonyl compounds is reported. With 2‐aryl‐2H‐indazoles as the substrates, α‐diazo carbonyl compounds could act as a C2 synthon to afford 5,6‐disubstituted indazolo[2,3‐a]quinolines via a Rh(III)‐catalyzed [4+2] annulation. On
通过Rh(III)催化的2-芳基-2 H-吲唑与α-重氮羰基化合物的无氧化剂环氧化反应选择性合成5,6-二取代和5-取代的吲唑并[2,3- a ]喹啉是报告。以2-芳基-2 H-吲唑为底物,α-重氮羰基化合物可作为C2合成子,通过Rh(III)催化[ 5,6-二取代的吲唑并[2,3- a ]喹啉] [4 +2]。另一方面,当使用2-芳基-3-甲酰基-2 H-吲唑类作为底物时,α-重氮羰基化合物转变为C1合成子,需要经历更复杂的[5 + 1]环化工艺来提供5位取代的吲哚并[2,3- a ]喹啉。
Cp*Ir(<scp>iii</scp>)-catalyzed C–H/N–H functionalization of sulfoximines for the synthesis of 1,2-benzothiazines at room temperature
作者:Yogesh N. Aher、Dhanaji M. Lade、Amit B. Pawar
DOI:10.1039/c8cc03288b
日期:——
The first Cp*Ir(III)-catalyzed C–H/N–H bond functionalization of sulfoximines with α-diazocarbonyl compounds has been developed for the synthesis of 1,2-benzothiazines under redox-neutral conditions. The reactions proceed at roomtemperature with excellent functional group tolerance and high yields without the requirement of any silver additive.
Regioselective Syntheses of 1,2-Benzothiazines by Rhodium-Catalyzed Annulation Reactions
作者:Ying Cheng、Carsten Bolm
DOI:10.1002/anie.201501583
日期:2015.10.12
Rhodium‐catalyzed directed carbene insertions into aromatic CH bonds of S‐aryl sulfoximines lead to intermediates, which upon dehydration provide 1,2‐benzothiazines in excellent yields. The domino‐type process is regioselective and shows a high functional‐group tolerance. It is scalable, and the only by‐products are dinitrogen and water. Three illustrative transformations underscore the synthetic
Catalytic, Cascade Ring‐Opening Benzannulations of 2,3‐Dihydrofuran
<i>O</i>
,
<i>O</i>
‐ and
<i>N</i>
,
<i>O</i>
‐Acetals
作者:Joel Aponte‐Guzmán、Lien H. Phun、Marchello A. Cavitt、J. Evans Taylor、Jack C. Davy、Stefan France
DOI:10.1002/chem.201601954
日期:2016.7.18
An Al(OTf)3‐catalyzed intramolecular cascade ring‐opening benzannulation of 2,3‐dihydrofuran O,O‐ and N,O‐acetals is described. The cascade sequence involves the dihydrofuran ring‐opening by acetal hydrolysis, an intramolecular Prins‐type cyclization, and aromatization to generate an array of benzo‐fused (hetero)aromatic systems in up to 95 % yield. This method represents the first example of dihydrofuran