Hydrazines and Azides via the Metal-Catalyzed Hydrohydrazination and Hydroazidation of Olefins
作者:Jérôme Waser、Boris Gaspar、Hisanori Nambu、Erick M. Carreira
DOI:10.1021/ja062355+
日期:2006.9.1
which the H and the N atoms come from two different reagents, a silane and an oxidizing nitrogen source (azodicarboxylate or sulfonyl azide). The hydrohydrazination reaction using di-tert-butyl azodicarboxylate is characterized by its ease of use, large functional group tolerance, and broad scope, including mono-, di-, tri-, and tetrasubstituted olefins. Key to the development of the hydroazidation
报道了 Co 和 Mn 催化的烯烃加氢肼和加氢叠氮化反应的发现、研究和实施。这些反应等效于 CC 双键与受保护的肼或偶氮酸的直接加氢胺化,但基于不同的概念,其中 H 和 N 原子来自两种不同的试剂,硅烷和氧化性氮源(偶氮二羧酸或磺酰叠氮化物) )。使用偶氮二羧酸二叔丁酯的加氢肼反应具有使用方便、官能团耐受性大、适用范围广的特点,包括单、二、三和四取代烯烃。氢叠氮化反应发展的关键是使用磺酰叠氮化物作为氮源和叔丁基过氧化氢的活化作用。发现该反应对于单、二和三取代烯烃的官能化是有效的,并且只有少数官能团是不能容忍的。获得的烷基叠氮化物是通用中间体,可以在不分离叠氮化物的情况下转化为游离胺或三唑。初步的机理研究表明,烯烃的氢化钴是限速的,然后是胺化反应。不能排除并可能涉及自由基中间体。然后进行胺化反应。不能排除并可能涉及自由基中间体。然后进行胺化反应。不能排除并可能涉及自由基中间体。
Terminal Alkenes from Acrylic Acid Derivatives via Non-Oxidative Enzymatic Decarboxylation by Ferulic Acid Decarboxylases
作者:Godwin A. Aleku、Christoph Prause、Ruth T. Bradshaw-Allen、Katharina Plasch、Silvia M. Glueck、Samuel S. Bailey、Karl A. P. Payne、David A. Parker、Kurt Faber、David Leys
DOI:10.1002/cctc.201800643
日期:2018.9.7
Fungal ferulic acid decarboxylases (FDCs) belong to the UbiD‐family of enzymes and catalyse the reversible (de)carboxylation of cinnamic acidderivatives through the use of a prenylated flavin cofactor. The latter is synthesised by the flavin prenyltransferase UbiX. Herein, we demonstrate the applicability of FDC/UbiX expressing cells for both isolated enzyme and whole‐cell biocatalysis. FDCs exhibit
Model Guided Development of a Simple Catalytic Method for the Synthesis of Unsymmetrical Stilbenes by Sequential Heck Reactions of Aryl Bromides with Ethylene
作者:Helen Barlow、Jonas Y. Buser、Hendrik Glauninger、Carla V. Luciani、Joseph R. Martinelli、Niall Oram、Nichole Thompson‐Van Hook、Jeffery Richardson
DOI:10.1002/adsc.201800167
日期:2018.7.16
moieties, but methods for their preparation typically possess numerous inefficiencies. Presented here is a methodology for the two‐step, one pot preparation of unsymmetrical stilbenes via sequential Heck reactions. The first Heck reaction with ethylene gas was analysed as a function of temperature and pressure for electronically differentiated naphthyl bromides and model‐aided reaction optimization was utilized
A three-component reaction of olefin, diselenide and water, alcohols, phenol, carboxylic acid, or amine by a commercially available hypervalent iodine(III) reagent, PhIO, was developed. This method provides access to a wide range of vicinally functionalized selenoderivatives under ambient conditions with mostly excellent yields and high diastereoselectivity. The developed reaction displays high levels
products, which correspond to reaction patterns of amido-azidation, benzoyloxy-azidation, and diazidation. The electronic nature of the aryl group attached to the olefin moiety was found to play a crucial role in determining the reaction consequence: when the aryl group was electron-rich, the reactions afforded benzoyloxy-azidation products exclusively; for highly electron-deficient vinyl arenes, by contrast