A carbamoyl-substituted nitrileoxide was generated upon treatment of easily available 2-methyl-4-nitro-3-isoxazolin-5(2H)-one with THF (not dried); the reaction proceeded efficiently even in the absence of any special reagents and reaction conditions. The nitrileoxide caused 1,3-dipolarcycloaddition with common aliphatic nitriles or electron-rich aromatic nitriles to afford 3-functionalized 1,2
Mechanistic Rationalization of Unusual Sigmoidal Kinetic Profiles in the Machetti–De Sarlo Cycloaddition Reaction
作者:Matthew P. Mower、Donna G. Blackmond
DOI:10.1021/ja512753v
日期:2015.2.18
Unusual sigmoidal kineticprofiles in the Machetti-De Sarlo base-catalyzed 1,3-dipolar cycloaddition of acrylamide to N-methylnitroacetamide are rationalized by detailed in situ kinetic analysis. A dual role is uncovered in which a substrate acts as a precursor to catalyze its own reaction. Such kinetic studies provide a general protocol for distinguishing among different mechanistic origins of induction
通过详细的原位动力学分析,Machetti-De Sarlo 碱催化的丙烯酰胺向 N-甲基硝基乙酰胺的 1,3-偶极环加成反应中异常的 S 形动力学曲线得以合理化。揭示了一种双重作用,其中底物充当催化其自身反应的前体。这种动力学研究提供了一个通用协议,用于区分复杂有机反应中诱导期的不同机械起源。
Conjugate Addition versus Cycloaddition/Condensation of Nitro Compounds in Water: Selectivity, Acid-Base Catalysis, and Induction Period
作者:Luca Guideri、Francesco De Sarlo、Fabrizio Machetti
DOI:10.1002/chem.201202698
日期:2013.1.7
react in water as in chloroform with electron‐deficient dipolarophiles to give condensation or conjugate addition products under basecatalysis. In general, high selectivity towards condensation is observed in water, with shorter induction periods than in chloroform. In water, condensations slowly occur even without base; kinetic profiles evidence the catalytic effect of the base, which should be related
A nitrile oxide containing a carbamoyl group is readily generated upon the treatment of 2-methyl-4-nitro-3-isoxazolin-5(2H)-one with water under mild reaction conditions, even in the absence of special reagents. The obtained nitrile oxide undergoes cycloaddition with dipolarophiles, alkynes and alkenes, to afford the corresponding isoxazol(in)es, which are useful intermediates in the synthesis of polyfunctionalized