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。
A Supramolecular Model for the Co‐Catalytic Role of Nitro Compounds in Brønsted Acid Catalyzed Reactions
作者:Joel J. Montalvo‐Acosta、Marian Dryzhakov、Edward Richmond、Marco Cecchini、Joseph Moran
DOI:10.1002/chem.202000368
日期:2020.8.26
Nitro compounds are known to change reaction rates and kinetic concentration dependence of Brønsted‐acid‐catalyzed reactions. Yet, no mechanistic model exists to account for these observations. In this work, an atomistic model for the catalytically active form for an alcohol dehydroazidation reaction is presented, which is generated by DFT calculations and consists of an H‐bonded aggregate of two molecules
作者:Tjark H. Meyer、Ramesh C. Samanta、Antonio Del Vecchio、Lutz Ackermann
DOI:10.1039/d0sc05924b
日期:——
Manganaelectro-catalyzed azidation of otherwise inert C(sp3)–H bonds was accomplished using most user-friendly sodium azide as the nitrogen-source. The operationally simple, resource-economic C–H azidation strategy was characterized by mild reaction conditions, no directing group, traceless electrons as the sole redox-reagent, Earth-abundant manganese as the catalyst, high functional-group compatibility
使用大多数用户友好的叠氮化钠作为氮源,完成了锰电催化的惰性 C(sp 3 )–H 键的叠氮化。操作简单、资源经济的C-H叠氮化策略具有反应条件温和、无导向基团、无痕电子作为唯一氧化还原试剂、地球丰富的锰作为催化剂、高官能团相容性和高化学选择性等特点。生物活性化合物的后期叠氮化阶段。通过实验、分光光度法和循环伏安法进行的详细机理研究为金属催化脂肪族自由基的形成以及随后在锰( III / IV )流形内的叠氮基自由基转移提供了强有力的支持。
Catalytic B(C6F5)3H2O-promoted defluorinative functionalization of tertiary aliphatic fluorides
A B(C6F5)3H2O-catalyzed defluorinative functionalization of tertiary aliphaticfluorides is described that proceeds under benign reaction conditions. The synthetic utility of the method is exemplified through the fast and efficient formation of a range of products with newly installed C(sp3) N, S, C and O bonds. This study illustrates the broad reactivity of otherwise inert starting materials and provides
描述了在良性反应条件下进行的AB(C 6 F 5)3 H 2 O催化的叔脂肪族氟化物的脱氟官能化。通过快速有效地形成一系列具有新安装的C(sp 3)N,S,C和O键的产品,可以举例说明该方法的综合用途。这项研究说明了其他惰性原料的广泛反应性,并提供了通往有价值的和合成上代表性不足的产品的途径,这些产品以前从未从此类氟化前体中获得。
An Enantioselective Bidentate Auxiliary Directed Palladium-Catalyzed Benzylic C−H Arylation of Amines Using a BINOL Phosphate Ligand
作者:Hao Wang、Hua-Rong Tong、Gang He、Gong Chen
DOI:10.1002/anie.201609337
日期:2016.12.5
A new enantioselective palladium(II)‐catalyzed benzylic C−Harylation reaction of amines is enabled by the bidentate picolinamide (PA) directing group. This reaction provides the first example of enantioselective benzylic γ‐C−Harylations of alkyl amines, and proceeds with up to 97 % ee. The 2,2′‐dihydroxy‐1,1′‐binaphthyl (BINOL) phosphoric acid ligand, Cs2CO3, and solvent‐free conditions are essential
二齿吡啶甲酰胺(PA)导向基团可实现新的对映选择性钯(II)催化的胺的苄基CH芳基化反应。该反应提供了烷基胺对映选择性苄基γ-C-H芳基化的第一个实例,并以高达97%的ee进行。2,2'-二羟基-1,1'-联萘(BINOL)磷酸配体Cs 2 CO 3和无溶剂条件对于高对映选择性至关重要。机理研究表明,多个BINOL配体参与立体确定CH palpalation步骤。