<sup>1</sup>H NMR, IR and UV/VIS Spectroscopic Studies of Some Schiff Bases Derived from 2-Aminobenzothiazole and 2-Amino-3-Hydroxypyridine
作者:Raafat M. Issa、Abdalla M. Khedr、Helen Rizk
DOI:10.1002/jccs.200800131
日期:2008.8
benzaldehyde and 4-dimethylaminobenzaldehyde, and five Schiffbases la-Ie are prepared. Also, two Schiffbases IIa and IIb are prepared by condensation of 2-amino-3-hydroxypyridine with 2-hydroxy-l-naphthaldehyde and 2-hydroxybenzaldehyde. The 1 H NMR, IR and UV/Vis spectra of these seven Schiffbases are investigated. The signals of the 1 H NMR spectra as well as the important bands in the IR spectra
An NHC-catalyzed regio- and stereoselective Mannich/lactamization dominoreaction of N-(benzothiazolyl)imines with alpha-chloroaldehydes has been developed. This new protocol provides a facile approach for the asymmetric synthesis of benzothiazolo-pyrimidinones and a pyrrolo[1,2-a]indolone in moderate to good yields (34-78%) and excellent stereoselectivities (87-99% ee, up to >20 : 1 d.r.).
Regiodivergent Synthesis of Benzothiazole‐Based Isosorbide Imidates by Oxidative N‐Heterocyclic Carbene Catalysis
作者:Daniele Ragno、Carmela De Risi、Alessandro Massi、Graziano Di Carmine、Sofia Toldo、Costanza Leonardi、Olga Bortolini
DOI:10.1002/ejoc.202200482
日期:2022.8.5
The regiodivergent synthesis of exo (2-OH) and endo (5-OH) isosorbide (IS) imidates containing biologically relevant N-heterocyclic rings (benzothiazole, benzoxazole, thiazole and isoxazole) has been achieved by oxidative N-heterocyclic carbene (NHC) catalysis starting from aldimine starting materials. A large library of unprecedented high value-added products has been obtained with good levels of
Three-Component One-Pot Construction of 2-Aryl-4<i>H</i>-benzo[4,5]thiazolo[3,2-<i>a</i>]pyrimidines Using Solid Calcium Carbide as a Surrogate of Gaseous Acetylene
作者:Zeshuai Zhang、Zhiqiang Wang、Zheng Li
DOI:10.1021/acs.orglett.2c02331
日期:2022.7.29
A concise method for the construction of 2-aryl-4H-benzo[4,5]thiazolo[3,2-a]pyrimidines usingsolidcalciumcarbide instead of gaseous acetylene as an alkynesource and 2-aminobenzothiazoles and aromatic aldehydes as substrates through one-pot three-component cascade reactions is described. The salient features for this protocol are the use of an inexpensive and easy-to-handle alkynesource, noble-metal-free
一种使用固体电石代替气态乙炔作为炔烃源,2-氨基苯并噻唑和芳香醛作为底物构建 2-aryl-4 H-苯并[4,5]噻唑并[3,2 - a ]嘧啶的简明方法通过一锅三组分级联反应进行了描述。该协议的显着特点是使用廉价且易于处理的炔烃源、无贵金属条件、宽底物范围和功能耐受性、令人满意的产量和简单的后处理程序。