31697-95-7Relevant academic research and scientific papers
The synthesis of pyrroles and dihydropyrroles by 1,3-dipolar cyclisations of N-arylmethylene[(benzotriazol-1-yl)arylmethyl]amines
Katritzky,Hitchings,Zhao
, p. 863 - 867 (2007/10/02)
N-Arylmethylene[(benzotriazol-1-yl)arylmethyl]amines 1 are prepared by the reaction of arylaldehydes, benzotriazole, and ammonia in dry ethanol. Deprotonation of these imines with butyllithium yields N-lithiated azomethine ylides 2 which readily undergo 1,3-dipolar cycloaddition with a large range of dipolarophiles. The cyclisations are regiospecific and generally exhibit high stereoselectivity. Benzotriazolate is eliminated during the course of the reaction, and the method thereby provides a route to 2,5-diaryl substituted pyrroles, 3,4-dihydro-2H-pyrroles and c-ring fused 3,4-dihydro-2H-pyrroles.
Michael Addition and Alkylation of 2-Azaallyl Anions Derived from N-(1-Cyanoalkyl)imines, and Stereoselective Cyclization of Imine Esters or Ketones Leading to 1-Pyrrolines
Tsuge, Otohiko,Ueno, Kazunori,Kanemasa, Shuji,Yorozu, Kiyotaka
, p. 3347 - 3358 (2007/10/02)
The 2-azaallyl anions derived from N-(1-cyanoalkyl)imines and DBU undergo Michael addition or alkylation to produce N-(1-alkylated 1-cyanoalkyl)imines.The Michael addition of some aryl-substituted imines are highly diastereoselective.The alkylated Michael adducts are converted into lactams through a hydrolysis and recyclization sequence.Base-induced cyclization furnishes 1-pyrroline through a cyclization and HCN elimination sequence.In the latter reaction, 4,5-cis-1-pyrrolines are selectively produced when the adducts are treated with LDA in the presence of lithium iodide.
Metallic Base-Induced Cycloadditions of N-(1-Cyanoalkyl)imines via N-Metalated Azomethine Ylides: Enhanced Reactivity and High Regio- and Stereoselectivity
Tsuge, Otohiko,Kanemasa, Shuji,Yorozu, Kiyotaka,Ueno, Kazunori
, p. 3359 - 3366 (2007/10/02)
Lithiation of N-(1-cyanoalkyl)imines with LDA generates new N-lithiated azomethine ylide 1,3-dipoles which show enhanced reactivity toward dipolarophiles.They undergo exclusively regio- and stereoselective 3+2 cycloaddition reaction with α,β-unsaturated e
Stereoselectivity of Cycloaddition of N-(Cyanomethyl)- and N-(α-Cyanobenzyl)imines with Olefinic Dipolarophiles. Synthetic Equivalents of Nitrile Ylide 1,3-Dipoles
Tsuge, Otohiko,Ueno, Kazunori,Kanemasa, Shuji,Yorozu, Kiyotaka
, p. 1809 - 1824 (2007/10/02)
N-(Cyanomethyl)- and N-(α-cyanobenzyl)imines derived from a variety of aldehydes and ketones can tautomerize into N-protonated azomethine ylides which undergo cycloadditions with olefinic dipolarophiles.These cycloadditions are often accompanied by the el
