Cp*Co(III)-Catalyzed γ-Selective C–H Allylation/Hydroamination Cascade for the Synthesis of Dihydroisoquinolines
作者:Suh Young Choi、Hyeon Dae Kim、Jong-Un Park、Sun-a Park、Ju Hyun Kim
DOI:10.1021/acs.orglett.9b03977
日期:2019.12.20
A Cp*Co(III)-catalyzed γ-selective C-H allylation/hydroamination cascade toward the synthesis of 3,4-dihydroisoquinolines (DHIQs) has been successfully developed, starting from NH ketimines and allyl carbonates. Notably, highly efficient and γ-selective C-H allylations were accomplished using γ-substituted allyl reagents, thus overcoming the issues of poor α/γ selectivity and low reactivity of previous
Iridium complex-catalyzed allylic amination of allylic carbonates was studied. The solvent strongly affected the catalytic activity. The use of a polar solvent such as EtOH is essential for obtaining the products in high yield, The reaction of (E)-3-substituted-2-propenyl carbonate and 1-substituted-2-propenyl carbonate with pyrrolidine in the presence of a catalytic amount of [Ir(COD)Cl](2) and P(OPh)(3) (P/Ir = 2) gave a branch amine with up to 99% selectivity. Both secondary and primary amines could be used for this reaction. When a primary amine was used, selective monoallylation occurred. No diallylation product was obtained. The reaction of 1,1-disubstituted-2 propenyl acetate with amines exclusively gave an alpha,alpha -disubstituted allylic amine. This reaction provides an alternative route to the addition of an organometallic reagent to ketimines. for the preparation of such amines. The reaction of (Z)-3-substituted-2-propenyl carbonate with amines gave (Z)-linear amines with up to 100% selectivity. In all cases, no (E)-linear amine was obtained. The selectivities described here have not been achieved in similar palladium complex-catalyzed reactions.
Complete Retention of <i>Z</i> Geometry in Allylic Substitution Catalyzed by an Iridium Complex
作者:Ryo Takeuchi、Norihito Shiga
DOI:10.1021/ol990033n
日期:1999.7.1
[GRAPHICS]The Z geometry of methyl (Z)-3-monosubstituted-2-alkenyl carbonate was completely retained in iridium complex-catalyzed allylic amination. The reaction of methyl (Z)-2-nonenyl carbonate with piperidine in the presence of a catalytic amount of [Ir(COD)Cl](2) and P(OPh)(3) at 50 degrees C for 2 h gave a 98:2 mixture of (Z)-1-(2-nonenyl)piperidine and 1-(1-n-hexyl-2-propenyl)piperidine in 86% yield, No E isomer was obtained. Various (Z) allylic amines were obtained in 91-100% selectivity by allylic amination of methyl (Z) 3-monosubstituted-2-alkenyl carbonate.
Electrochemical Synthesis of Allylic Amines from Terminal Alkenes and Secondary Amines
作者:Diana J. Wang、Karina Targos、Zachary K. Wickens
DOI:10.1021/jacs.1c11763
日期:2021.12.29
electrophilic adduct between thianthrene and the alkene substrates. Treatment of these adducts with aliphatic amine nucleophiles and base provides allylic amine products in high yield. This synthetic strategy is also amenable to functionalization of feedstock gaseous alkenes at 1 atm. In the case of 1-butene, high Z-selective crotylation is observed. This strategy, however, is not limited to the synthesis of
The palladium-catalyzed allylic substitution (Tsuji-Trost) reaction is widely applied in organicsynthesis, especially for the synthesis of stereochemically well-defined olefins. However, the synthesis of Z-olefins via the Tsuji-Trost reaction has been challenging due to the thermodynamic instability of the corresponding anti-π-allyl-palladium intermediate. Here, we report a ligand-enabled palladium-catalyzed