728006-01-7Relevant academic research and scientific papers
Ligand-Controlled Regiodivergence for Catalytic Stereoselective Semireduction of Allenamides
Hajiloo Shayegan, Mojtaba,Li, Zhong-Yuan,Cui, Xin
, (2021/12/02)
Ligand-controlled regiodivergence has been developed for catalytic semireduction of allenamides with excellent chemo- and stereocontrol. This system also provides an example of catalytic regiodivergent semireduction of allenes for the first time. The divergence of the semireduction is enabled by ligand switch with the same palladium pre-catalyst under operationally simple and mild conditions. Monodentate ligand XPhos exclusively promotes selective 1,2-semireduction to afford allylic amides, while bidentate ligand BINAP completely switched the regioselectivity to 2,3-semireduction, producing (E)-enamide derivatives.
Dynamic Kinetic Resolution in Gold-Catalyzed (4 + 2)-Annulations between Alkynyl Benzaldehydes and Allenamides to Yield Enantioenriched All-Carbon Diarylalkylmethane Derivatives
Pandit, Yashwant Bhaskar,Liu, Rai-Shung
, p. 548 - 553 (2022/01/20)
This work reports the synthesis of diarylmethane derivatives via gold-catalyzed (4 + 2)-annulations between alkynyl benzaldehydes and allenamides, followed by an aza-Claisen rearrangement. Deuterium labeling and crossover experiments have been performed to confirm this proposed mechanism. With racemic 3-substituted allenamides in a substrate ratio (1:1), we employ chiral gold catalysts to achieve a dynamic kinetic resolution to obtain enantioenriched diarylalkylmethane derivatives with high e.r. levels (up to 93:7).
Gold-Catalyzed Intermolecular Formal [4 + 2 + 2]-Cycloaddition of Anthranils with Allenamides
Wang, Cheng,Xu, Guangyang,Shao, Ying,Tang, Shengbiao,Sun, Jiangtao
supporting information, p. 5990 - 5994 (2020/08/12)
The construction of eight-membered rings is a challenging issue due to unfavorable transannular strain and entropic barriers. We report herein a gold-catalyzed formal [4 + 2 + 2] cycloaddition reaction of anthranils with allenamides to deliver oxa-bridged eight-membered heterocycles in accepted yields with unique E/Z configuration. Moreover, the asymmetric [4 + 2 + 2] cycloaddition by using chiral phosphoramidite gold catalyst has also been conducted.
Copper-catalysed hydroamination of N-allenylsulfonamides: The key role of ancillary coordinating groups
Blieck, Rémi,Perego, Luca Alessandro,Ciofini, Ilaria,Grimaud, Laurence,Taillefer, Marc,Monnier, Florian
, p. 1225 - 1234 (2019/02/26)
A copper-catalysed hydroamination reaction of N-allenylsulfonamides with amines has been developed through a rational approach based on mechanistic studies. The reaction is promoted by a simple copper(I) catalyst and proceeds at room temperature with complete regioselectivity and excellent stereoselectivity towards linear (E)-N-(3-aminoprop-1-enyl)sulfonamides. Density Functional Theory (DFT) studies allow interpreting the key role of unsaturated substituents on nitrogen as ancillary coordinating moieties for the copper catalyst.
Gold-Catalyzed 1,2-Oxyalkynylation of N-Allenamides with Ethylnylbenziodoxolones
Banerjee, Somsuvra,Senthilkumar, Beeran,Patil, Nitin T.
supporting information, p. 180 - 184 (2019/01/11)
A gold-catalyzed 1,2-oxyalkynylation of N-allenamides with ethylnylbenziodoxolones (EBXs) has been achieved for the first time. The reaction, which follows a redox-neutral Au(I)/Au(III) catalytic pathway, was enabled in an attempt to exhaust the EBX reagents atom-economically by putting the nucleophilic carboxylate part of EBXs to appropriate use. This constitutes the first example for gold-catalyzed β-alkynylation of N-allenamides to construct highly valuable 1,3-enynes. The potential of the sequence is further documented by some follow-up transformations.
Transition-Metal-Free Stereoselective Borylation of Allenamides
García, Lorena,Sendra, Jana,Miralles, Núria,Reyes, Efraim,Carbó, Jorge J.,Vicario, Jose L.,Fernández, Elena
, p. 14059 - 14063 (2018/09/10)
Complete stereocontrol on the transition-metal-free hydroboration of the distal double bond of allenamides could be achieved when allenamides contained acetyl substituents, which provided exclusively the Z-isomer. The consecutive Pd-catalyzed cross-coupli
[3+2]-Annulation of platinum-bound azomethine ylides with distal C=C bonds of N-allenamides
Chakrabarty, Indradweep,Inamdar, Suleman M.,Akram, Manjur O.,Gade, Amol B.,Banerjee, Subhrashis,Bera, Saibal,Patil, Nitin T.
, p. 196 - 199 (2016/12/27)
A Pt-catalyzed, highly regioselective reaction between N-allenamides and imino-alkynes leading to pyrrolo[1,2-a]indoles is described. This represents the first example of [3+2]-annulation of Pt-bound azomethine ylides with the distal C=C bond of N-allenam
Enantioselective Oxidative (4+3) Cycloadditions between Allenamides and Furans through Bifunctional Hydrogen-Bonding/Ion-Pairing Interactions
Villar, Laura,Uria, Uxue,Martínez, Jose I.,Prieto, Liher,Reyes, Efraim,Carrillo, Luisa,Vicario, Jose L.
, p. 10535 - 10538 (2017/08/22)
BINOL-based N-trifluoromethanesulfonyl phosphoramides catalyze the enantioselective (4+3) cycloaddition between furans and oxyallyl cations, the latter being generated in situ by oxidation of allenamides. The chiral organic phosphoramide counteranion is proposed to engage in the activation of the oxyallyl cation intermediate through cooperative hydrogen-bonding and ion-pairing interactions, enabling an efficient chirality transfer that provide the final adducts with high diastereo- and enantioselectivities. Remarkably, the reaction shows a wide substrate scope that includes a variety of substituted allenamides and furans.
Regioselective 1,2-addition of allenamides with: N -haloimides: Synthesis of 2-halo allylic aminal derivatives
Li, Hong-He,Li, Xiao-Xiao,Zhao, Zhi-Gang,Yuan, Xiao,Sun, Chen-Yang
, p. 4005 - 4013 (2017/07/11)
A strategy for the synthesis of 2-halo allylic aminal derivatives through regioselective 1,2-addition of allenamides with N-haloimides is presented. This reaction was conducted under very mild conditions and gave up to 99% yield. Moreover, the obtained ha
Gold(i) operational in synergistic catalysis for the intermolecular α-addition reaction of aldehydes across allenamides
Ballesteros, Alberto,Morán-Poladura, Pablo,González, Jose M.
supporting information, p. 2905 - 2908 (2016/02/19)
The intermolecular reaction of allenamides with aldehydes is reported. The designed approach relies on gold(i) and organocatalysis for activating the allenamides and the aldehydes respectively. Conditions to achieve an enantioselective version of this int
