18294-89-8Relevant academic research and scientific papers
Iridium-Catalyzed Aerobic α,β-Dehydrogenation of γ,δ-Unsaturated Amides and Acids: Activation of Both α- And β-C-H bonds through an Allyl-Iridium Intermediate
Wang, Zhen,He, Zhiqi,Zhang, Linrui,Huang, Yong
supporting information, p. 735 - 740 (2018/01/26)
Direct aerobic α,β-dehydrogenation of γ, δ-unsaturated amides and acids using a simple iridium/copper relay catalysis system is described. We developed a new strategy that overcomes the challenging issue associated with the low α-acidity of amides and acids. Instead of α-C-H metalation, this reaction proceeds by β-C-H activation, which results in enhanced α-acidity. Conjugated dienamides and dienoic acids were synthesized in excellent yield with this reaction, which uses a simple reaction protocol. Mechanistic experiments suggest a catalyst resting state mechanism in which both α-C-H and β-C-H cleavage is accelerated.
Gold I-catalyzed highly diastereo- and enantioselective alkyne oxidation/cyclopropanation of 1,6-enynes
Qian, Deyun,Hu, Haoxiang,Liu, Feng,Tang, Bin,Ye, Weimin,Wang, Yidong,Zhang, Junliang
supporting information, p. 13751 - 13755 (2015/02/19)
A highly enantioselective oxidative cyclo-propanation of 1,6-enynes catalyzed by cationic AuI/ chiral phophoramidite complexes is presented. The new method provides convenient access to densely functionalized bicyclo[3.1.0]hexanes bearing three contiguous quaternary and tertiary stereogenic centers with high enantioselectivity (up to e.r. 98:2). Control experiments suggest that the quinoline moiety of the b-gold vinyloxyquinolinium intermediate in the reaction plays an important role in promoting good enantiose-lectivity through a transitional auxiliary effect in the transition state.
Ortho-substituted iodobenzenes as novel organocatalysts for bromination of alkenes
Braddock, D. Christopher,Cansell, Gemma,Hermitage, Stephen A.
, p. 2483 - 2485 (2008/03/28)
Suitably ortho-substituted iodobenzenes act as organocatalysts for the transfer of electrophilic bromine from N-bromosuccinimide to alkenes via the intermediacy of bromoiodinanes. The Royal Society of Chemistry 2006.
Reagent-Controlled Asymmetric Iodolactonization Using Cinchona Alkaloids as Chiral Sources
Wang, Mang,Gao, Lian Xun,Yue, Wei,Mai, Wen Peng
, p. 1023 - 1032 (2007/10/03)
A novel method for reagent-controlled asymmetric iodolactonization of 5-aryl-4-pentenoic acids is reported. This work uses carboxylate ion pairs combined with cinchona alkaloids as chiral sources of carboxylate anion for the first time leading to a mixture of two regio-isomeric iodolactones with moderate enantioselectivity (exo-18.5% ee, endo-35.0% ee) under mild reaction conditions.
Z/E-Isomerization of Unsaturated Carboxylic Acids during the Kolbe Electrolysis
Huhtasaari, Matti,Schaefer, Hans J.,Luftmann, Heinrich
, p. 537 - 548 (2007/10/02)
Z-4-Enoic acids partially isomerize to E-configurated products in the Kolbe electrolysis.The results from methyl and deuterium labelled carboxylic acids 2 and 16 support an isomerization via a reversible ring closure to cyclopropylcarbinyl radicals.The double bonds of Z-N-enoic acids with N>/= 5 fully retain their configuration in the Kolbe electrolysis; for N=6,7 cyclic products are formed to some extent, which is in accord with the reactivity of 5- and 6-alkenyl radicals.
