Hydroxide-ion-initiated reactions under phase-transfer catalysis conditions. 9. Dehydrohalogenation of (haloethyl)benzenes by quaternary ammonium salts
traditional C −C cross‐coupling reactions they have been rarely used and Pd catalysts usually give a superior performance. Herein we report that in situ formed gold metal nanoparticles are highly active catalysts for the crosscoupling of allylstannanes and activated alkylbromides to form C −C bonds. Turnover numbers up to 29 000 could be achieved in the presence of active carbon as solidsupport, which allowed
Catalytic Carbocation Generation Enabled by the Mesolytic Cleavage of Alkoxyamine Radical Cations
作者:Qilei Zhu、Emily C. Gentry、Robert R. Knowles
DOI:10.1002/anie.201604619
日期:2016.8.16
weak C−O bond. Spontaneous scission results in the formation of the stable nitroxyl radical TEMPO. as well as a reactive carbocation intermediate that can be intercepted by a wide range of nucleophiles. Notably, this process occurs underneutralconditions and at comparatively mild potentials, enabling catalytic cation generation in the presence of both acid sensitive and easily oxidized nucleophilic
Synthesis of Alcohols from <i>m</i>-Fluorophenylsulfones and Dialkylboranes: Application to the C14–C35 Building Block of E7389
作者:Lei Liu、James A. Henderson、Akihiko Yamamoto、Paul Brémond、Yoshito Kishi
DOI:10.1021/ol300672q
日期:2012.5.4
hydroperoxide oxidation, yields alcohols in high yields. Optimization of the process, scope and limitation, and application to the synthesis of one of the C14–C35 building blocks of E7389, a right half analogue of halichondrin B, are reported.
Scalable anti-Markovnikov hydrobromination of aliphatic and aromatic olefins
作者:Marzia Galli、Catherine J. Fletcher、Marc del Pozo、Stephen M. Goldup
DOI:10.1039/c6ob00692b
日期:——
To improve access to a key synthetic intermediate we targeted a direct hydrobromination-Negishi route. Unsurprisingly, the anti-Markovnikov addition of HBr to estragole in the presence of AIBN proved successful. However, even in the absence of an added initiator, anti-Markovnikov addition was observed. Re-examination of early reports revealed that selective Markovnikov addition, often simply termed
α-Chiral alkyl primaryamines are virtually universal synthetic precursors for all other α-chiral N-containing compounds ubiquitous in biological, pharmaceutical, and material sciences. The enantioselective amination of common alkyl halides with ammonia is appealing for potential rapid access to α-chiral primaryamines, but has hitherto remained rare due to the multifaceted difficulties in using ammonia