在此,我们提出了一种 Cu I-二聚体,[Cu I {Ph 2 PC 6 H 4 C( O )NC 6 H 4 PPh 2 - o }] 2 ,它催化了苄基和具有优异产率和区域选择性的环烷烃衍生物。该方法非常简单并且可以容忍各种功能。在 Cu-N 键断裂和氮质子化中观察到协同金属-配体协同作用,并促进双功能途径,最大限度地减少催化中间体的自由能波纹。
Zur Kenntnis des Kohlenstoffringes. 58. Mitteilung Über die Reaktion einiger vielgliedriger Cycloalkyl-bromide mit Magnesium
作者:L. Ruzicka、P. Barman、V. Prelog
DOI:10.1002/hlca.19510340144
日期:——
10gliedrigen Cycloalkyl-bromide in ätherischer Lösung mit Magnesium und Umsetzung des erhaltenen Reaktionsproduktes mit Kohlendioxyd wurden neben kleineren Mengen Cycloalkan-carbonsäuren hauptsächlich Kohlenwasserstoff-Gemische erhalten, die aus Cycloalken, Cycloalkan und Dicycloalkyl bestehen. Dieses ungewöhnliche Verhalten wird auf die leichte Bildung der freien Cycloalkyl-Radikale mit einer mittleren Ringgliederzahl
Bei-der Reaktion der 7- bis 10gliedrigen环烷基溴化物,位于德国的镁和铀矿石中。DiesesungewöhnlicheVerhalten wird auf die leichte Bildung der freien环烷基-Radikale mit einer mittleren Ringgliederzahlzurückgeführt。
Alkane functionalization on a preparative scale by mercury-photosensitized cross-dehydrodimerization
作者:Stephen H. Brown、Robert H. Crabtree
DOI:10.1021/ja00190a032
日期:1989.4
5-trioxacyclohexane < ethanol < isobutane < THF < Etsub3}SiH. The observed selectivities generally parallel those for homodimerization, reported in the preceding paper, but certain differences are noted, and reasons for the differences are proposed. The bond-dissociation energymore » of Etsub3}SiH is estimated from the reactivity data to be 90 kcal/mol. Eleven new carbinols are synthesized. 39 refs., 6 tabs
photolysis of thiols and tert-butyl peroxyformate. In the gas phase, reactions of H atoms generally result in the vibrationally excited radicals which lead to extensive fragmentations. However, in the liquid phase, the atoms were found to be less reactive. The reactions of H atoms with olefins were performed in a flow system at 2 torr, the H atoms being generated by microwave discharge (2540-MHz, 60-W output)
该实验室以前的结果表明,微波放电是一种方便且有效的氧原子源,用于有机合成,处于凝聚相。现在作者报告说,这个来源也提供了一种产生相同目的的氢原子的极好方法。H 原子与有机底物在液相和气相中的反应已被广泛研究。为此目的,主要通过 H2 的放电、水和有机液体的辐射分解以及硫醇和过甲酸叔丁酯的光解产生 H 原子。在气相中,H 原子的反应通常会产生振动激发的自由基,从而导致广泛的碎裂。然而,在液相中,发现原子的反应性较低。H 原子与烯烃的反应在 2 torr 的流动系统中进行,由 H2 和 He (1:50) 的混合物的微波放电(2540-MHz,60-W 输出)产生的 H 原子。排出的气体通过纯液体或基材溶液。由于发现丙酮对 H 原子呈惰性,因此作者在这些反应中将其用作溶剂。
A Structure–Activity Study of Ni-Catalyzed Alkyl–Alkyl Kumada Coupling. Improved Catalysts for Coupling of Secondary Alkyl Halides
作者:Peng Ren、Oleg Vechorkin、Kim von Allmen、Rosario Scopelliti、Xile Hu
DOI:10.1021/ja200270k
日期:2011.5.11
of several well-defined Ni catalysts that are significantly more active and efficient than the pincercomplex [((Me)N(2)N)NiCl] for the coupling of secondary alkyl halides. The best two catalysts are [((H)NN)Ni(PPh(3))Cl] and [((H)NN)Ni(2,4-lutidine)Cl]. The improved activity and efficiency was attributed to the fact that phosphine and lutidine ligands in these complexes can dissociate from the Ni
对 Ni 催化的烷基-烷基熊田型交叉偶联反应进行了结构-活性研究。合成了一系列新的镍(II)配合物,包括具有三齿钳状双(氨基)酰胺配体((R)N(2)N)和具有双齿混合氨基-酰胺配体((R)NN)的配合物并对其进行了结构表征. 这些配合物的配位几何形状从方形平面、四面体到方形金字塔形。该配合物已被研究作为未活化的烷基卤化物,特别是仲烷基碘化物与烷基格氏试剂交叉偶联的预催化剂。与先前报道的 Ni 钳形复合物 [((Me)N(2)N)NiCl] 获得的结果进行了比较。预催化剂中的金属转移位点对于催化是必需的。预催化剂的配位几何形状和自旋状态影响很小或没有影响。这项工作导致发现了几种明确定义的 Ni 催化剂,这些催化剂比钳形复合物 [((Me)N(2)N)NiCl] 更活跃、更有效,用于偶联仲烷基卤化物。最好的两种催化剂是 [((H)NN)Ni(PPh(3))Cl] 和 [((H)NN)Ni(2
Mono- and Disubstituted N,N-Dialkylcyclopropylamines from Dialkylformamides via Ligand-Exchanged Titanium–Alkene Complexes Part 79 in the series “Cyclopropyl Building Blocks for Organic Synthesis”. For part 78 see: M. Gensini, I. Kozhushkov, S. Yufit, K. Howard, M. Es-Sayed, de Meijere, Eur. J. Org. Chem. 2002, 2499–2507; part 77: H. Nüske, S. Bräse, I. Kozhushkov, M. Noltemeyer, M. Es-Sayed, de Meijere, Chem. Eur. J. 2002, 8, 2350–2369.
作者:Armin de Meijere、Craig M. Williams、Alexandre Kourdioukov、Sergei V. Sviridov、Vladimir Chaplinski、Markus Kordes、Andrei I. Savchenko、Christian Stratmann、Mathias Noltemeyer
Dibenzylformamide was treated with cyclohexylmagnesium bromide in the presence of either titanium tetraisopropoxide or methyltitanium triisopropoxide and a variety of cyclic and acyclic alkenes and alkadienes to give new mono- and disubstituted as well as bicyclic dialkylcyclopropylamines (Tables 1-3) in yields ranging from 18 to 90 % (in most cases around 55 %). 3-Benzyl-6-(N,N-dibenzylamino)-3-azabicyclo[3