31594-55-5Relevant academic research and scientific papers
Synthesis of 1-Pyrroline by Denitrogenative Ring Expansion of Cyclobutyl Azides under Thermal Conditions
Ban, Kazuho,Miki, Yuya,Sajiki, Hironao,Sawama, Yoshinari,Tomita, Naohito
, p. 3481 - 3484 (2021/06/17)
We herein report an efficient and systematic synthesis of 1-pyrrolines from cyclobutyl azides under thermal and neutral conditions. The reaction proceeded without any additional reagents, and nitrogen was generated as the sole by-product. Furthermore, the generated 1-pyrrolines could be continuously transformed into pyrroles, N-Boc-amines, and oxaziridines in an one-pot manner. (Figure presented.).
Solvent and Aryl-Substituent Effects on the Rates of Thermal Decomposition of α-Azidostyrenes
Jordan, David
, p. 3584 - 3587 (2007/10/02)
The effect on the rates of first-order thermolysis of α-azidostyrenes by aryl substitution have been measured in benzyl alcohol and 1-butanol in the temperature range 60-100 deg C.Values for ΔH(excit) are in the range 24-28 kcal/mol, and for ΔS(excit), +1 to -9 eu.The rate constants of the meta and para substituents are correlated with ?+ substituent constants where ρ = -0.7 (r = 0.98) in both solvents.Relative to α-azidostyrene, 2-methyl-α-azidostyrene and 2,4,6-trimethyl-α-azidostyrene experience retardation of thermolysis by factor of 0.97 and 0.58, respectively, in 1-butanol at 80 deg C.The activation parameters, ρ value, ?+ rate correlation, and the steric retardation support a concerted mechanism where, in the transition state, positive charge is delocalized to the aryl ring, coplanarity of the developing azirine ring and the aryl ring being required.Thermolysis rates of α-azidostyrene at 80.2 deg C are little affected by changes in solvent polarity, but are markedly accelerated in methyl acrylate, in which ΔH(excit) = 20 kcal/mol and ΔS(excit) = -17 eu, supporting a hypothesis by others that this reaction does not produce a nitrene intermediate, as was first suggested, but is likely a 1,3-dipolar cycloaddition mechanism of the azide function of α-azidostyrene with methyl acrylate to give a triazoline, which rapidly loses nitrogen.
Regioselective Cycloadditions of N-Protonated Azomethine Ylides and 2-Azaallyl Anions Generated from N-(Silylmethyl) Thioimidates, Synthetic Equivalents of Nonstabilized Nitrile Ylides
Tsuge, Otohiko,Kanemasa, Shuji,Yamada, Toshiaki,Matsuda, Koyo
, p. 2523 - 2530 (2007/10/02)
A water-induced-desilylation method and a direct-desilylation method have been applied to N-(silylmethyl) thioimidates to lead to the generation of N-protonated azomethine ylides and 2-azaallyl anions, respectively.These reactive intermediates are capture
Silyl-Substituted Thioimidates as Nitrile Ylide Equivalents
Padwa, Albert,Gasdaska, John R.,Haffmanns, Gunter,Rebello, Hector
, p. 1027 - 1035 (2007/10/02)
Treatment of silyl-substituted thioimidates with silver fluoride in the presence of a trapping agent produces dipolar cycloadducts formally derived from nitrile ylides.The ratio of cycloadducts obtained from the reaction of unsymmetrically substituted dip
