Unsymmetrical <i>E</i>-Alkenes from the Stereoselective Reductive Coupling of Two Aldehydes
作者:Keyhan Esfandiarfard、Juri Mai、Sascha Ott
DOI:10.1021/jacs.7b00428
日期:2017.3.1
The unprecedented formation of unsymmetrical alkenes from the intermolecular reductive coupling of two different aldehydes is described. In contrast to the McMurry reaction which affords statistical product mixtures, selectivity in the reported procedure is achieved by a sequential ionic mechanism in which a first aldehyde is reacted with a phosphanylphosphonate to afford a phosphaalkene intermediate
<i>Z</i>
‐Selective Alkene Formation from Reductive Aldehyde Homo‐Couplings
作者:Juri Mai、Anna I. Arkhypchuk、Sebastian Wagner、Andreas Orthaber、Sascha Ott
DOI:10.1002/ejoc.202200365
日期:2022.9.13
The presence of an electron-withdrawing group at the PIII of a phosphanyl phosphonate reagent MesFP(H)P(O)(OEt)2 (see Figure) renders the reductive aldehyde coupling of aldehydes selectively for the thermodynamically less stable Z-olefin product.
膦酰基膦酸酯试剂 Mes F P(H)P(O)(OEt) 2的 P III上存在吸电子基团(见图)使得醛的还原性醛偶联选择性地用于热力学不太稳定的Z -烯烃产物。
Molybdenum–Quinone-Catalyzed Deoxygenative Coupling of Aromatic Carbonyl Compounds
In the presence of triphenylphosphine as a mild reductant, the use of catalytic amounts of Mo(CO)6 and an ortho-quinone ligand enables the intermolecular reductive coupling of aromatic aldehydes and the intramolecular coupling of aromatic ketones to produce functionalized alkenes. Diaryl- and diheteroaryl alkenes are synthesized with high (E)-selectivity and a tolerance toward bromide, iodide, and steric
在三苯膦作为温和还原剂存在的情况下,使用催化量的 Mo(CO) 6和邻醌配体能够实现芳香醛的分子间还原偶联和芳香酮的分子内偶联以产生官能化烯烃。二芳基和二杂芳基烯烃的合成具有高 ( E ) 选择性和对溴化物、碘化物和空间位阻的耐受性。在类似条件下二羰基化合物的分子内偶联得到单取代和双取代的菲。
Synthesis of oligo(2-ethynylpyridines): novel building blocks for supramolecular systems
New oligo(2-ethynylpyridines) 1 are synthesized as novel building blocks for the construction of supramolecular systems by the coupling reaction of the novel dibromopyridines 2 with ethynylpyridines 3. (C) 2002 Elsevier Science Ltd. All rights reserved.