Eco-friendly construction of spiroquinazolin-2-(thi)ones and quinolin-(thio)ureas <i>via</i> Fe(<scp>iii</scp>)-catalyzed multi-component domino double [4 + 2] annulations
作者:Zhentao Pan、Shuaijun Shi、Xuancheng Yang、Xuqiong Xiao、Wangqin Zhang、Shiliang Wang、Yongmin Ma
DOI:10.1039/d1gc00889g
日期:——
An unprecedented eco-friendly multi-component domino approach for the synthesis of spiroquinazolin-2-(thi)ones and quinolin-(thio)ureas via Fe(iii)-catalyzed domino double [4 + 2] cycloadditions is described.
strategy, we broke this consensus and discovered a catalyst-free photodecarbonylation of the aldehyde group. It revealed that decarbonylation can be easily achieved with visible light irradiation by introducing a tertiary amine into the ortho-position of the aldehyde group. A diverse array of tertiary amines is tolerated by our photodecarbonylation under mild conditions. Furthermore, the (QM) computations
4-c]quinolone derivatives were synthesized via domino Knoevenagel-hetero-Diels–Alder reactions of indoline-2-thions and novel N-acrylated anthranilaldehydes in refluxing ethanol as a solvent in the presence of 20 mol% ZnBr2 as a Lewisacid catalyst. All reactions proceed with high yields with excellent regio- and stereoselectivity.
在20 mol的乙醇存在下,通过吲哚-2-噻吩的多米诺胺Knoevenagel-杂Diels-Alder反应和新颖的N-丙烯酸蒽醛在回流的乙醇中合成了各种新型的[3,4- c ]喹诺酮衍生物。%ZnBr 2作为路易斯酸催化剂。所有反应均以高产率进行,具有优异的区域选择性和立体选择性。
Diastereoselective Synthesis of Novel Pyrrolidine or Pyrrolizine-Fused Benzo-δ-sultams via 1,3-Dipolar Cycloadditions
The synthesis of novel pyrrolidine or pyrrolizine‐fused benzosultams is described. A number of (E)‐N‐(2‐formylphenyl)‐N‐alkyl‐2‐phenylethenesulfonamides derivatives were synthesized and subjected to intramolecular [3 + 2] cycloaddition with azomethine ylides derived in situ from the reaction with sarcosine, phenylglycine, and L‐proline.
Chemodivergent Spirocyclization of 2‐Sec‐Aminobenzilidene Imidazolones: Lewis Versus Brønsted Acids Catalysis
作者:Dmitrii S. Ivanov、Elvira R. Zaitseva、Alexander Yu. Smirnov、Dina A. Rustamova、Andrey A. Mikhaylov、Maria A. Sycheva、Darya A. Gluschenko、Nadezhda S. Baleeva、Mikhail S. Baranov
DOI:10.1002/adsc.202200109
日期:2022.4.26
Benzylidene imidazolones with ortho- secondary aminogroup undergo acid-promoted chemodivergent spirocyclization. Strong Lewisacids provide access to spirocyclic tetrahydroquinolines via [1,5]-hydride shift triggered cyclization despite of the presence of free secondary amino group. Brønstedacids promote unprecedented intramolecular umpolung hydroamination reaction with the formation of spirocyclic indolines