Asymmetric Synthesis of Adjacent Tri‐ and Tetrasubstituted Carbon Stereocenters: Organocatalytic Aldol Reaction of an Hydantoin Surrogate with Azaarene 2‐Carbaldehydes
作者:June Izquierdo、Noémie Demurget、Aitor Landa、Tore Brinck、Jose M. Mercero、Peter Dinér、Mikel Oiarbide、Claudio Palomo
DOI:10.1002/chem.201902817
日期:2019.9.20
A bifunctional amine/squaramide catalyst promoted direct aldol addition of an hydantoin surrogate to pyridine 2-carbaldehyde N-oxides to afford adducts bearing two vicinal tertiary/quaternary carbons in high diastereo- and enantioselectivity (d.r. up to >20:1; ee up to 98 %) is reported. Acid hydrolysis of adducts followed by reduction of the N-oxide group yields enantiopure carbinol-tethered quaternary
An Efficient Method for Synthesis of Thiohydantoins with a-Amino Esters Under Microwave Irradiation
作者:Yanmei Zhao、Zhouyu Wang、Zhenju Jiang、Hualin Feng、Li Liu、Ju Wang
DOI:10.14233/ajchem.2014.16119
日期:——
An efficient and simple way for synthesis of thiohydantoins is reported. In the absence of any additional catalysts, a series of thiohydantoins were synthesized with amino esters and isothiocyanates in aqueous medium under microwave irradiation. Excellent isolated yields (up to 98 %) were obtained under mild conditions.
Unprecedented One-Pot Chemocontrolled Entry to Thioxoimidazolidinones and Aminoimidazolones: Synthesis of Kinase Inhibitor Leucettamine B
作者:Manikandan Selvaraju、Chung-Ming Sun
DOI:10.1021/co500152s
日期:2015.3.9
A novel and highly chemoselective protocol for the construction of thioxoimidazolidinone and aminoimidazolone frameworks was explored, and the influence of the reaction conditions on product formation was studied to establish two distinct approaches for their selective formation. In this one-pot reaction, ambient temperature generally resulted in the formation of thioxoimidazolidinones, whereas microwave irradiation provided aminoimidazolones exclusively. An attempt to elucidate the observed chemoselectivity is described, and the products were confirmed by X-ray studies. One-pot synthesis toward Leucettamine B, a marine alkaloid, was achieved on the basis of this protocol.
Microwave Assisted Synthesis of 1,3,4-Oxadiazole/Thiohydantoin Hybrid Derivatives via Dehydrative Cycliztion of Semicarbazide
作者:Seung-Ju Yang、Jae-Min Lee、Gee-Hyung Lee、NaYeon Kim、Yong-Sang Kim、Young-Dae Gong
DOI:10.5012/bkcs.2014.35.12.3609
日期:2014.12.20
eduReceived July 29, 2014, Accepted September 16, 2014A series of compounds containing both 1,3,4-oxadiazole and thiohydantoin were synthesized as a promisingscaffold for application in medicinal chemistry. The key step of the synthesis is a microwave-assistedcyclization of semicarbazides possessing a thiohydantoin moiety at one of the acyl termini using POCl