Quantum-chemistry-aided identification, synthesis and experimental validation of model systems for conformationally controlled reaction studies: Separation of the conformers of 2,3-dibromobuta-1,3-diene in the gas phase [PDF]
The Diels-Alder cycloaddition, in which a diene reacts with a dienophile to form a cyclic compound, counts among the most important tools in organic synthesis. Achieving a precise understanding of its mechanistic details on the quantum level requires new experimental and theoretical methods.
arxiv +1 more source
Spatial Separation of the Conformers of Methyl Vinyl Ketone [PDF]
Methyl vinyl ketone (C$_4$H$_6$O) is a volatile, labile organic compound of importance in atmospheric chemistry. We prepared a molecular beam of methyl vinyl ketone with a rotational temperature of 1.2(2)~K and demonstrated the spatial separation of the \emph{s-cis} and \emph{s-trans} conformers of methyl vinyl ketone using the electrostatic deflector.
arxiv +1 more source
Ferrocene-derived P,N ligands : synthesis and application in enantioselective catalysis [PDF]
Due to their unique steric and electronic properties, air-stability and modular structure, chiral hybrid P,N-ferrocenyl ligands play a prominent role in the field of asymmetric catalysis.
Noël, Timothy, Van der Eycken, Johan
core +1 more source
1,3-Dipolar cycloadditions of isatins, benzylamine and benzylideneacetones were studied to prepare a series of novel spiropyrrolidine-oxindoles – 4′-acetyl-3′,5′-diarylspiro[indoline-3,2′-pyrrolidin]-2-ones and 3′-acetyl-4′,5′-diarylspiro[indoline-3,2 ...
Chuqin Peng+5 more
doaj +1 more source
Enhanced Sampling for Free Energy Profiles with Post-Transition-State Bifurcations [PDF]
We present a method to explore the free energy landscapes of chemical reactions with post-transition-state bifurcations using an enhanced sampling method based on well-tempered metadynamics. Obviating the need for computationally expensive DFT-level ab initio molecular dynamics simulations, we obtain accurate energetics by utilizing a free energy ...
arxiv +1 more source
Asymmetric 1,3-Dipolar Cycloadditons of Stabilized Azomethine Ylides with Nitroalkenes [PDF]
This review highlights the biological importance of many polysubstituted nitro-prolines and -pyrrolidines. Their preparation using asymmetric 1,3-dipolar cycloadditions of azomethine ylides with nitroalkenes using diastereoselective and enantioselective ...
Nájera, Carmen, Sansano, Jose M.
core +2 more sources
Reaction profiles for quantum chemistry-computed [3 + 2] cycloaddition reactions [PDF]
Bio-orthogonal click chemistry based on [3 + 2] dipolar cycloadditions has had a profound impact on the field of biochemistry and significant effort has been devoted to identify promising new candidate reactions for this purpose. To gauge whether a prospective reaction could be a suitable bio-orthogonal click reaction, information about both on- and ...
arxiv
Cavity Click Chemistry: Cavity-Catalyzed Azide-Alkyne Cycloaddition [PDF]
Click chemistry, which refers to chemical reactions that are fast, selective, and with high product yields, has become a powerful approach in organic synthesis and chemical biology. Due to the cytotoxicity of the transition metals employed in click chemistry reactions, a search for novel metal-free alternatives continues.
arxiv
[4 + 2] Cycloadditions of diphenylketene with a highly substituted 1,3-diene [PDF]
Diphenylketene (2) undergoes [4 + 2] cycloadditions with the s-cis fixed diene (1) to give the dihydropyran (3) and the cyclohexenone (4)
Heigl, Ulrich W., Mayr, Herbert
core +1 more source
1,3-Dipolar cycloadditions of fluorinated nitrones with thioketones [PDF]
AbstractReadily available fluorinated nitrones (IV) and (XIV) are used in 1,3‐dipolar cycloadditions with thioketones affording 1,4,2 oxathiazolidines in a regioselective manner.
Mlostoń, Grzegorz+5 more
openaire +3 more sources