77887-48-0Relevant academic research and scientific papers
Oxidative asymmetric umpolung alkylation of Evans' β-ketoimides using dialkylzinc nucleophiles
Targel, Tom A.,Kumar, Jayprakash N.,Shneider, O. Svetlana,Bar, Sukanta,Fridman, Natalia,Maximenko, Shimon,Szpilman, Alex M.
supporting information, p. 2546 - 2549 (2015/04/14)
Umpolung alkylation of Evans' auxiliary substituted β-ketoimides affords the diastereomerically pure products in yields ranging from 40 to 80%. The reaction itself proceeds with diastereoselectivities between 3:1 and 18:1. Dialkylzinc serves as the nucleo
Design and application of a low-temperature continuous flow chemistry platform
Newby, James A.,Blaylock, D. Wayne,Witt, Paul M.,Pastre, Julio C.,Zacharova, Marija K.,Ley, Steven V.,Browne, Duncan L.
, p. 1211 - 1220 (2014/12/10)
A flow reactor platform technology applicable to a broad range of low temperature chemistry is reported. The newly developed system captures the essence of running low temperature reactions in batch and represents this as a series of five flow coils, each with independently variable volume. The system was initially applied to the functionalization of alkynes, Grignard addition reactions, heterocycle functionalization, and heteroatom acetylation. This new platform has then been used in the preparation of a 20-compound library of polysubstituted, fluorine-containing aromatic substrates from a sequential metalation-quench procedure and can be readily adapted to provide gaseous electrophile inputs such as carbon dioxide using a tube-in-tube reactor.
Assembly intermediates in polyketide biosynthesis: Enantioselective syntheses of β-hydroxycarbonyl compounds
Sann, Christine Le,Munoz, Dulce M.,Saunders, Natalie,Simpson, Thomas J.,Smith, David I.,Soulas, Florilene,Watts, Paul,Willis, Christine L.
, p. 1719 - 1728 (2007/10/03)
A versatile approach for the enantioselective synthesis of functionalised β-hydroxy N-acetylcysteamine thiol esters has been developed which allows the facile incorporation of isotopic labels. It has been shown that a remarkable reversal of selectivity occurs in the titanium mediated aldol reaction of acyloxazolidinone 7 using either (S)- or (R)-tert-butyldimethylsilyloxybutanal. The aldol products are valuable intermediates in the synthesis of 4-hydroxy-6-substituted δ-lactones. The Royal Society of Chemistry 2005.
Electrogenerated base-induced N-acylation of chiral oxazolidin-2-ones. 2
Feroci, Marta,Inesi, Achille,Palombi, Laura,Sotgiu, Giovanni
, p. 1719 - 1721 (2007/10/03)
An improved and efficient electrochemical N-acylation of chiral oxazolidin-2-ones has been achieved. The generation of the nitrogen anion is obtained under mild conditions and without addition of base or probase, by direct electrolysis of a solution of Me
A convenient method for synthesis of optically active methylphenidate from N-methoxycarbonylpiperidine by utilizing electrochemical oxidation and Evans aldol-type reaction
Matsumura, Yoshihiro,Kanda, Yasuhisa,Shirai, Kimihiro,Onomura, Osamu,Maki, Toshihide
, p. 7411 - 7422 (2007/10/03)
A new method to prepare optically active methylphenidate starting from piperidine is described. The method consists of a transformation of N-methoxycarbonylated piperidine to the corresponding α-methoxylated carbamate utilizing electrochemical oxidation f
A general synthesis of homochiral β-hydroxy N-acetylcysteamine thioesters
Le Sann, Christine,Simpson, Thomas J.,Smith, David I.,Watts, Paul,Willis, Christine L.
, p. 4093 - 4096 (2007/10/03)
A convenient and efficient route for the enantioselective synthesis of functionalised β-hydroxy N-acetylcysteamine thioesters is described. The route allows the facile incorporation of vicinal 13C labelling to produce intermediates required for biosynthetic studies on a wide range of polyketide metabolites, e.g. 6-MSA, monocerin, colletodiol and strobilurins.
Methods for the synthesis of L-leucine selectively labelled with carbon-13 or deuterium in either diastereotopic methyl group
Kelly,Kelly, Nicholas M.,Reid,Gordon Reid,Willis,Willis, Christine L.,Winton,Winton, Peter L.
, p. 8315 - 8318 (2007/10/02)
A versatile approach is described for the enantioselective synthesis of isotopically labelled L-leucine involving the preparation of 4-methylpentanoic acid labelled selectively with carbon-13 or deuterium in either the pro-R or pro-S methyl group followed by a reductive amination of the ketone catalysed by leucine dehydrogenase. This strategy is applied to the total synthesis of (2S,4R)-[5,5,5-D3]-leucine using CD3I as the source of deuterium.
Asymmetric Aldol Reactions. Use of the Titanium Enolate of a Chiral N-Acyloxazolidinone To Reverse Diastereofacial Selectivities
Nerz-Stormes, Maryellen,Thornton, Edward R.
, p. 2489 - 2498 (2007/10/02)
Aldol reactions of the titanium enolate of (S)-N-propionyl-4-isopropyl-2-oxazolidinone (readily derived from L-valine) with representative aldehydes give high diastereofacial selectivities for the syn aldol adducts expected from chelation control.This represents a remarkable reversal in selectivity compared with the corresponding boron enolate, thus permitting either enantiomeric form of β-hydroxy-α-methyl carboxylic acids to be made from a single, readily available oxazolidinone simply by changing the metal.A lithium interference effect is shown to be easily prevented by use of excess titanium.Use of diethyl ether as solvent rather than THF significantly enhances the stereoselectivity.Mechanistically, the observed stereochemical reversal constitutes very strong evidence that chelation is operative with titanium, presumably through a chelated chairlike transition structure.In this transition structure, the conformation would be rigidly locked by chelation and the titanium would be at least hexacoordinate, resulting in a "superaxial" ligand, thus nicely explaining the high stereocontrol.
