作者:Wei Wei、Xi-Jie Dai、Haining Wang、Chenchen Li、Xiaobo Yang、Chao-Jun Li
DOI:10.1039/c7sc04207h
日期:——
Natural availability of carbonyl groups offers reductive carbonyl coupling tremendous synthetic potential for efficient olefin synthesis, yet the catalytic carbonyl cross-coupling remains largely elusive. We report herein such a reaction, mediated by hydrazine under ruthenium(II) catalysis. This method enables facile and selective cross-couplings of two unsymmetrical carbonyl compounds in either an
羰基的自然可用性为有效的烯烃合成提供了还原性羰基偶联的巨大合成潜力,但催化羰基的交叉偶联仍然很难实现。我们在本文中报道了在钌(II)催化下由肼介导的这种反应。该方法能够以分子间或分子内的方式使两种不对称羰基化合物容易且选择性地交叉偶联。此外,该化学物质可容纳多种底物,在温和的反应条件下以良好的官能团耐受性进行,并产生化学计量的良性副产物。重要的是,KO t Bu和双齿膦dmpe的共存对于这种转化至关重要。
Ruthenium catalyzed β-selective alkylation of vinylpyridines with aldehydes/ketones <i>via</i> N<sub>2</sub>H<sub>4</sub> mediated deoxygenative couplings
作者:Leiyang Lv、Chao-Jun Li
DOI:10.1039/d0sc06586b
日期:——
aldehyde/ketones via N2H4 mediated deoxygenative couplings. Compared with one-electron umpolung of carbonyls to alcohols, this two-electron umpolung strategy realized reductive deoxygenation targets, which were not only applicable to the regioselective alkylation of a broad range of 2/4-alkene substituted pyridines, but also amenable to challenging 3-vinyl and steric-embedded internal pyridines as well as their
N-Amino-1,8-naphthalimide was used as a protectinggroup and a reagent to selective synthesis of various mono-N-substituted hydrazines and hydrazides. In all these reactions, the protecting reagent N-amino-1,8-naphthalimide was easily regenerated in good yields by the hydrazinolysis. All these transformations showed good functional-group tolerance and can be used for large scale C−N cross-coupling
Advanced measuring techniques for the production of ultra-thin hot strip
作者:M. Degner、K.-E. Friedrich、H. W. Tamler、G. Thiemann、U. Müller
DOI:10.1051/metal:2001108
日期:2001.6
When producing ultra-thin hot strip, the yield and economy depend on achieving narrow geometrical and material properties fulfilling the increased customers demand. In production, the correct measurement of the strip properties is necessary. This paper gives advanced measuring and control techniques for the parameters concerning thickness profile, flatness profile, coil face profile, temperature profile, surface finish profile of ultra-thin hot rolled strip.
Die Bildung von Hexahydro-1,2,4,5-tetrazinderivaten bei der Reaktion von Aldehyden mit Hydrazin
作者:W. Skorianetz、E. Sz. Kováts
DOI:10.1002/hlca.19700530206
日期:——
The cristalline reaction products of acetaldehyde and some of its higher straight chain homologues with one equivalent of hydrazine are shown to be 3, 6-dialkyl-hexahydro-1, 2, 4, 5-tetrazines (1) which can be oxidized to the corresponding 3, 6-dialkyl-1, 2, 4, 5-tetrazines.