163748-80-9Relevant articles and documents
Stereospecific Synthesis of α-Hydroxy-Cyclopropylboronates from Allylic Epoxides
Amenós, Laura,Trulli, Laura,Nóvoa, Luis,Parra, Alejandro,Tortosa, Mariola
supporting information, p. 3188 - 3192 (2019/01/25)
Herein, we report a catalytic and stereospecific method for the preparation of enantioenriched α-hydroxy cyclopropylboronates with control in four contiguous stereocenters. The reaction involves the borylation of readily available allylic epoxides using an inexpensive Cu(I) salt and a commercially available phosphine ligand. High diastereocontrol is achieved and different diastereomers can be selectively prepared. Functionalization of the carbon–boron bond provides access to different enantiomerically enriched trisubstituted cyclopropanes from a common intermediate.
Borylation and rearrangement of alkynyloxiranes: A stereospecific route to substituted α-enynes
Fuentespina, Ruben Pomar,De La Cruz, José Angel Garcia,Durin, Gabriel,Mamane, Victor,Weibel, Jean-Marc,Pale, Patrick
supporting information, p. 1416 - 1424 (2019/07/10)
1,3-Enynes are important building blocks in organic synthesis and also constitute the key motif in various bioactive natural products and functional materials. However, synthetic approaches to stereodefined substituted 1,3-enynes remain a challenge, as they are limited to Wittig and cross-coupling reactions. Herein, stereodefined 1,3-enynes, including tetrasubstituted ones, were straightforwardly synthesized from cis or trans-alkynylated oxiranes in good to excellent yields by a one-pot cascade process. The procedure relies on oxirane deprotonation, borylation and a stereospecific rearrangement of the so-formed alkynyloxiranyl borates. This stereospecific process overall transfers the cis or trans-stereochemistry of the starting alkynyloxiranes to the resulting 1,3-enynes.
Stereochemistry and biological activity of chlorinated lipids: A study of danicalipin A and selected diastereomers
Boshkow,Fischer,Bailey,Wolfrum,Carreira
, p. 6904 - 6910 (2017/10/05)
The syntheses of (+)-16-epi- and (+)-11,15-di-epi-danicalipin A (2 and 3) are reported. The conformations of the parent diols 5 and 6 as well as the corresponding disulfates 2 and 3 were determined on the basis of J-based configuration analysis and supported by calculations. The impact of configuration on membrane permeability in Gram-negative bacteria and mammalian cell lines was assessed as well as cytotoxicity. Although diastereomer 2 showed similar behavior to natural (+)-danicalipin A (1), strikingly, the more flexible C11,C15-epimer 3 had no effect on permeability and proved equally or more toxic towards multiple cell lines.
An organocatalytic one-pot cascade incorporating the Achmatowicz reaction affording 3-pyrone derivatives
Ransborg, Lars Krogager,Lykke, Lennart,Hammer, Niels,N?sborg, Line,J?rgensen, Karl Anker
supporting information, p. 7604 - 7606 (2014/07/08)
The development of an organocatalytic one-pot cascade for the annulation of simple starting materials: α,β-unsaturated aldehydes, hydrogen peroxide, β-carbonyl compounds and NBS to furnish optically active 3-pyrones in good yield and with excellent enanti
On the mechanism of the organocatalytic asymmetric epoxidation of α,β-unsaturated aldehydes
Davis, Rebecca L.,Jensen, Kim L.,Gschwend, Bjoern,Jorgensen, Karl Anker
supporting information, p. 64 - 67 (2014/01/17)
Mechanistic studies on the organocatalytic epoxidation of α,β-unsaturated aldehydes explore the autoinductive behavior of the reaction and establish that the hydrate/peroxyhydrate of the product is acting as a phase-transfer catalyst. Based on these studies, an improved methodology that provides high selectivities and decreased catalyst loading, through the addition of chloral hydrate, is developed. Self-promotion: Mechanistic studies on the organocatalytic epoxidation of α,β-unsaturated aldehydes reveal the autoinductive behavior and establish that the hydrate/peroxyhydrate of the product is acting as a phase-transfer catalyst. Based on these results, an improved methodology that provides high selectivities and decreased catalyst loading, through the addition of chloral hydrate, has been developed (see scheme). Copyright
Optically active thiophenes via an organocatalytic one-pot methodology
Ransborg, Lars Krogager,Albrecht, Lukasz,Weise, Christian F.,Bak, Jesper R.,Jorgensen, Karl Anker
supporting information; experimental part, p. 724 - 727 (2012/04/11)
A general methodology for the synthesis of trisubstituted, optically active thiophenes by an organocatalytic one-pot reaction cascade is presented. The target products are synthesized in good yields (up to 92%) and with excellent enantioselectivities (up to 98% ee). Importantly, based on practical and easily available starting materials, the presented methodology can be conducted under mild reaction conditions. To further elucidate the generality, the synthesis of optically active thienoindoles, as well as selenophenes, is also demonstrated.
Taming the friedel-crafts reaction: Organocatalytic approach to optically active 2,3-dihydrobenzofurans
Albrecht, Lukasz,Ransborg, Lars Krogager,Lauridsen, Vibeke,Overgaard, Mette,Zweifel, Theo,Jorgensen, Karl Anker
supporting information; experimental part, p. 12496 - 12500 (2012/01/15)
Fine-tuning: Three types of optically active trans-2,3-disubstituted-2,3- dihydrobenzofurans having three contiguous stereogenic centers can be efficiently accessed by one-pot reaction cascades (see scheme; TMS=trimethylsilyl). High substitution diversity of the final products can be achieved from the same common precursors by fine-tuning of their reactivity through simple structural modifications. Copyright
Organocatalytic strategies for the construction of optically active imidazoles, oxazoles, and thiazoles
Albrecht, ?ukasz,Ransborg, Lars Krogager,Albrecht, Anna,Lykke, Lennart,J?rgensen, Karl Anker
experimental part, p. 13240 - 13246 (2012/02/05)
This study demonstrates the first enantioselective synthesis of hydroxyalkyl- and aminoalkyl-substituted imidazoles, oxazoles, and thiazoles. The approach developed utilizes a highly effective one-pot reaction cascade that consists of either an organocatalytic epoxidation or aziridination of α,β-unsaturated aldehydes coupled with a [3+2]-annulation, in which amidines, ureas, or thioureas act as effective 1,3-dinucleophilic species. The methodology described benefits from low catalyst loadings, commercially and readily available starting materials, and mild reaction conditions.
Asymmetric epoxidation of α,β-unsaturated aldehydes in aqueous media catalyzed by resin-supported peptide-containing unnatural amino acids
Akagawa, Kengo,Kudo, Kazuaki
experimental part, p. 843 - 847 (2011/06/11)
The enantio- and diastereoselective epoxidation of α,β- unsaturated aldehydes in aqueous media was realized using a resin-supported peptide catalyst. Introducing the hydrophobic and bulky unnatural amino acid 3-(1-pyrenyl)alanine into the peptide sequence was effective for enhancing the reaction rate and enantioselectivity.
An organocatalytic approach to 2-hydroxyalkyl- and 2-aminoalkyl furanes
Albrecht, Lukasz,Ransborg, Lars Krogager,Gschwend, Bjoern,Jorgensen, Karl Anker
supporting information; experimental part, p. 17886 - 17893 (2011/02/23)
The first enantioselective methodology for the synthesis of electron-poor 2-hydroxyalkyl- and 2-aminoalkyl furanes is demonstrated in this study. It utilizes a highly stereoselective organocatalytic one-pot reaction cascade: epoxidation or aziridination o
