Zr4+-Catalyzed Efficient Synthesis of α-Aminophosphonates
作者:J. S. Yadav、B. V. S. Reddy、K. Sarita Raj、K. Bhaskar Reddy、A. R. Prasad
DOI:10.1055/s-2001-18444
日期:——
Aldimines undergo nucleophilic addition with diethyl phosphite in the presence of a catalytic amount of zirconiumtetrachloride at ambienttemperature to afford the corresponding α-aminophosphonates in high yields with high selectivity.
Development of a straightforward and efficient protocol for the one-pot multicomponent synthesis of substituted <i>alpha</i>-aminoallylphosphonates under catalyst-free condition
作者:Goutam Brahmachari、Sanchari Begam、Indrajit Karmakar、Vivek K Gupta
DOI:10.1080/10426507.2021.1920593
日期:2021.8.3
Abstract A catalyst-free practical version of Kabachnik-Fields strategy has been developed for the efficient and straightforward one-potsynthesis of diversely substituted α-aminoallylphosphonates, a limitedly reported class of biologically important α-aminophosphonates family. The protocol offers many advantages including avoidance of additive/catalyst, one-pot multicomponent approach, operational
摘要 Kabachnik-域策略的无催化剂的实际版本已经发展为高效和简单的一锅合成法多样取代α-aminoallylphosphonates的,一个有限报道类重要的生物的α -氨基膦酸酯家庭。该协议提供了许多优点,包括避免使用添加剂/催化剂、一锅多组分方法、操作简单、出色的区域选择性、良好的收率、相对较短的反应时间、克级适用性、高原子经济性和低 E 因子。
Superacid-promoted synthesis of quinoline derivatives
作者:Hien Vuong、Michael R. Stentzel、Douglas A. Klumpp
DOI:10.1016/j.tetlet.2020.151630
日期:2020.3
have been prepared from anilines and cinnamaldehydes. These substrates react in superacidic media to provide quinolines and related compounds. A mechanism for the conversion is proposed which involves the cyclization of dicationic superelectrophilic intermediates. Aromatization of the quinoline ring is thought to occur by superacid-promoted elimination of benzene.
N-Phenyl substituent controlled diastereoselective synthesis of β-lactam-isatin conjugates
作者:Lalitha Gummidi、Nagaraju Kerru、Paul Awolade、Collins U. Ibeji、Rajshekhar Karpoormath、Parvesh Singh
DOI:10.1016/j.tetlet.2020.151602
日期:2020.3
Unprecedented diastereoselective synthesis of novel β-lactam-isatin conjugates via a Staudinger [2+2] cycloaddition is described. The electronic nature of substituents on the imine N-phenyl moiety induced high levels of stereocontrol and plausibly controlled the competition between direct ring closure (conrotatory) and isomerization of the azabutadiene intermediate. The presence of electron-donating
Facile, Regioselective [4 + 2] Cycloaddition Involving 1-Aryl-4-phenyl-1-azadienes and Allenic Esters: An Efficient Route to Novel Substituted 1-Aryl-4-phenyl-1,4-dihydropyridines
作者:M. P. S. Ishar、Kamal Kumar、Sumanjit Kaur、Shiv Kumar、Navdeep K. Girdhar、Satish Sachar、Alka Marwaha、Ashish Kapoor
DOI:10.1021/ol010026a
日期:2001.7.1
undergo facile, regioselective [4 + 2] cycloaddition to the C2,C3 pi-bond of allenic esters in refluxing benzene, and the formed adducts undergo a 1,3-H shift to afford novel 2-alkyl-1-aryl-3-ethoxycarbonyl-4-phenyl-1,4-dihydropyridines (78-97%). However, when the reaction is carried at room temperature, besides the [4 + 2] addition, the [2 + 2] mode of addition involving C=N of azadiene and C3,C4 pi-bond