A case is described where intrusion of a primary incisor resulting in apical fenestration may have occurred secondary to occlusal forces. The effects on the permanent dentition and possible aetiological factors are discussed.
Aerobic Oxidative Amidation of Aromatic and Cinnamic Aldehydes with Secondary Amines by CuI/2-Pyridonate Catalytic System
作者:Mingwen Zhu、Ken-ichi Fujita、Ryohei Yamaguchi
DOI:10.1021/jo301553v
日期:2012.10.19
A simple and convenient CuI/2-pyridonate catalytic system for the oxidative amidation of aldehydes with secondary amines has been developed. With this system, a variety of useful arylamides have been synthesized in moderate to good yields in the presence of small amount of copper catalyst and the pyridonate ligand, generating only water as a coproduct. Synthesis of cinnamamides was also achieved by
Tertiary amine synthesis via reductive coupling of amides with Grignard reagents
作者:Lan-Gui Xie、Darren J. Dixon
DOI:10.1039/c7sc03613b
日期:——
reductive coupling reaction of Grignard reagents and tertiary amides affording functionalised tertiary amine products via an efficient and technically-simple one-pot, two-stage experimental protocol, is reported. The reaction – which can be carried out on gram-scale using as little as 1 mol% Vaska's complex [IrCl(CO)(PPh3)2] and TMDS as the terminal reductant for the initial reductive activation step –
ligand not only can facilitate the electrophilic aryl C–H rhodation but also can lower the olefin insertion barrier. Both electron-withdrawing and electron-donating directing groups such as -CONR2 and -NHAc could be employed in these reactions, which provides convenient routes toward a series styryl acetates, N-acetylindoles, and aryl methyl ketones.
尽管对过渡金属催化的Fujiwara–Moritani C–H型烯烃进行了广泛的研究,但这些转化中使用的烯烃仍主要限于活性丙烯酸酯和苯乙烯。富电子烯烃的选择性芳基CH烯化反应被认为是一个具有挑战性的问题。我们在本文中报道,简单且易于接近的缺电子的[CpRh(III)]和[Cp CF 3 Rh(III)](Cp CF 3 = C 5 Me 4 CF 3)配合物是富电子脱氢芳基化的有力催化剂烯烃,包括乙酸乙烯酯,酰胺和乙烯基醚。使用吸电子Cp或Cp CF 3配体代替特权Cp *(C5 Me 5)配体不仅可以促进亲电芳基C–H的铑基化,而且可以降低烯烃的插入势垒。在这些反应中都可以使用吸电子和供电子导向基团,例如-CONR 2和-NHAc,这提供了通向一系列乙酸苯乙烯酯,N-乙酰吲哚和芳基甲基酮的便捷途径。
Amide bond synthesis via silver(I) N-heterocyclic carbene-catalyzed and tert-butyl hydroperoxide-mediated oxidative coupling of alcohols with amines under base free conditions
free method for amide bond construction via oxidative coupling of alcohols with amines catalyzed by Silver(I) N-heterocyclic carbenes (Ag(I)-NHCs) and mediated by tert-butyl hydroperoxide (TBHP) in ethanol. The results of controlled experiments suggest that the oxidative coupling proceeds through the formation of aldehyde, then subsequent attack by amine to give hemiaminal, which can then be oxidized
Effect of the Temperature on the Stoichiometry of Borane Dimethyl Sulfide Reduction of Secondary and Tertiary Amides
作者:M. Bonnat、A. Hercouet、M. Le Corre
DOI:10.1080/00397919108021056
日期:1991.8
Abstract A simple procedure has been described for the reduction of secondary and tertiary amides to amines using borane-dimethyl sulfide in theoretical amounts.