216220-08-5Relevant articles and documents
Enantioselective α-Etherification of Branched Aldehydes via an Oxidative Umpolung Strategy
Corti, Vasco,J?rgensen, Karl Anker,Lamhauge, Johannes N.,Liu, Yidong
, p. 18728 - 18733 (2021/07/12)
Saturated carbonyl compounds are, via their enolate analogues, inherently nucleophilic at the α-position. In the presence of a benzoquinone oxidant, the polarity of the α-position of racemic α-branched aldehydes is inverted, allowing for an enantioselective etherification using readily available oxygen-based nucleophiles and an amino acid-derived primary amine catalyst. A survey of benzoquinone oxidants identified p-fluoranil and DDQ as suitable reaction partners. p-Fluoranil enables the preparation of α-aryloxylated aldehydes using phenol nucleophiles in up to 91 % ee, following either a one-step or a two-step, one-pot protocol. DDQ allows for a more general etherification protocol in combination with a broader range of alcohol nucleophiles with enantioselectivities up to 95 % ee. Control experiments and isolation of a key quinol intermediate supports a mechanism proceeding via an SN2 dynamic-kinetic resolution. These studies provide the basis for an aminocatalytic umpolung concept that allows for the asymmetric construction of tertiary ethers in the α-position of aldehydes.
Cu-Catalyzed [3 + 3] Cycloaddition of Isocyanoacetates with Aziridines and Stereoselective Access to α,γ-Diamino Acids
Kok, Germaine Pui Yann,Yang, Hui,Wong, Ming Wah,Zhao, Yu
, p. 5112 - 5115 (2018/09/12)
We report herein an efficient Cu-catalyzed formal [3 + 3] cycloaddition of isocyanoacetates with readily available aziridines of different substitution patterns, which provides a practical access to valuable 1,4,5,6-tetrahydropyrimidine derivatives. In pa
Enantioselective copper-catalyzed 1,4-addition of dialkylzincs to enones followed by trapping with allyl iodide derivatives
Kawamura, Kenjiro,Fukuzawa, Hitomi,Hayashi, Masahiko
, p. 640 - 647 (2011/08/06)
Enantioselective copper-catalyzed 1,4-addition of dialkylzincs to enones proceeded in the presence of 0.1 mol% of Cu(OTf)2 and 0.25 mol% of an N,N,P-ligand containing a quinoline moiety to afford the corresponding conjugated adducts in 99%ee. The intermediate zinc enolates were trapped with substituted allyl iodides to give disubstituted ketones with high diastereoselectivity and enantioselectivity.
ANTIFUNGAL AGENTS
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Page/Page column 59-60, (2010/04/03)
Novel derivatives of enfumafungin are disclosed herein, along with their pharmaceutically acceptable salts, hydrates and prodrugs. Also disclosed are compositions comprising such compounds, methods of preparing such compounds and methods of using such compounds as antifungal agents and/or inhibitors of (l,3)-β-D-glucan synthase. The disclosed compounds, their pharmaceutically acceptable salts, hydrates and prodrugs,,as well as compositions comprising such compounds, salts, hydrates and prodrugs, are useful for treating and/or preventing fungal infections and associated diseases and conditions.
ANTIFUNGAL AGENTS
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Page/Page column 46, (2010/04/03)
Novel derivatives of enfumafungin are disclosed herein, along with' their pharmaceutically acceptable salts, hydrates and prodrugs. Also disclosed are compositions comprising such compounds, methods of preparing such compounds and method of using such compounds as antifungal agents and/or inhibitors of (l,3)-β-D-glucan synthase. The disclosed compounds, their pharmaceutically acceptable salts, hydrates and prodrugs, as well as compositions comprising such compounds, salts, hydrates and prodrugs, are useful for treating and/or preventing fungal infections and associated diseases and conditions.
Novel N,N,P-tridentate ligands for the highly enantioselective copper-catalyzed 1,4-addition of dialkylzincs to enones
Kawamura, Kenjiro,Fukuzawa, Hitomi,Hayashi, Masahiko
supporting information; experimental part, p. 3509 - 3512 (2009/05/07)
(Chemical Equation Presented) Use of 0.25 mol % of the N,N,P-tridentate ligand containing the 2-quinolyl moiety (1 and 2) and 0.1 mol % of Cu(OTf) 2 enabled the enantioselective 1,4-addition of dialkylzincs to cyclic enones to produce 1,4-adduc
Chiral bicyclic guanidines: A concise and efficient aziridine-based synthesis
Ye, Weiping,Leow, Dasheng,Goh, Serena Li Min,Tan, Chin-Tong,Chian, Chee-Hoe,Tan, Choon-Hong
, p. 1007 - 1010 (2007/10/03)
A series of chiral bicyclic guanidines, either symmetrical or non-symmetrical, was synthesized using a concise and efficient aziridine-based synthetic methodology. Starting from commercial amino alcohols, five synthetic steps were performed, with only thr
Highly practical and enantioselective Cu-catalyzed conjugate addition of alkylzinc reagents to cyclic enones at ambient temperature
Krauss, Isaac J.,Leighton, James L.
, p. 3201 - 3203 (2007/10/03)
(Matrix presented) A new ligand for Cu-catalyzed enantioselective additions of dialkylzincs to cyclic enones has been developed. In addition to providing good to excellent enantioselectivities with a range of cyclic enones and dialkylzincs, the ligand has several notworthy features: it can be readily prepared in just two steps, is an air-stable crystalline solid, and provides optimal performance at ambient temperature.
Toward a versatile allylation reagent: Practical, enantioselective allylation of acylhydrazones using strained silacycles
Berger, Richard,Rabbat, Philippe M. A.,Leighton, James L.
, p. 9596 - 9597 (2007/10/03)
A highly practical method for the enantioselective allylation of acylhydrazones has been developed. The previously reported strained silacycle reagent 1 reacts with a wide variety of acylhydrazones to give the hydrazide products with good enantioselectivi
