34686-76-5Relevant academic research and scientific papers
Gold-Catalyzed Formal Hexadehydro-Diels-Alder/Carboalkoxylation Reaction Cascades
Wang, Hong-Fa,Guo, Lin-Na,Fan, Zhi-Bo,Tang, Tian-Hua,Zi, Weiwei
supporting information, p. 2676 - 2681 (2021/04/12)
A dual gold-catalyzed hexadehydro-Diels-Alder/carboalkoxylation cascade reaction is reported. In this transformation, the gold catalyst participated in the hexadehydro-Diels-Alder step, switching the mechanism from a radical type to a cationic one, and then the catalyst activated the resulting aryne to form an ortho-Au phenyl cation species, which underwent a carboalkoxylation rearrangement rather than the expected aryne-ene reaction.
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.
Lewis Acid-Promoted 3-Aza-Cope Rearrangement of N-Alkyl-N-allylanilines
Beholz, Lars G.,Stille, John R.
, p. 5095 - 5100 (2007/10/02)
The 3-aza-Cope rearrangement of N-alkyl-N-alkylaniline substrates, which required 250 deg C to proceed thermally, was promoted by Lewis acid reagents at 111-140 deg C.Systematic studies of this reaction were performed to examine a number of reaction variables such as concentration, the stoichiometry of the Lewis acid with the substrate, the optimum temperature for rearrangement, and the type of Lewis acid reagent.Of the many Lewis acids investigated, ZnCl2 (140 deg C) and Et2O*BF3 (111 deg C) were the most generally successful reagents for promoting the aromatic 3-aza-Cope rearrangement.With respect to substrate variation, the presence of a methoxy substituent para to the N-allyl group slowed the reaction slightly, while a meta substituent accelerated the rate of rearrangement and produced moderate site selectivity on the aromatic ring.Lewis acid-promoted rearrangement of an unsymmetrically substituted allyl moiety resulted in sigmatropic rearrangement to give the 1-hexen-3-yl substituent on the aromatic ring.Overall, both ZnCl2 and Et2O*BF3 were shown to efficiently accelerate the regiospecific 3-aza-Cope rearrangement of N-alkyl-N-allylanilines for the purpose of forming a carbon-carbon bond between a secondary alkyl substituent and an aromatic ring.
