168297-93-6Relevant articles and documents
Stereoselective Alkylation of Chiral Titanium(IV) Enolates with tert-Butyl Peresters
Pérez-Palau, Marina,Sanosa, Nil,Romea, Pedro,Urpí, Fèlix,López, Rosa,Gómez-Bengoa, Enrique,Font-Bardia, Mercè
, p. 8852 - 8856 (2021/11/17)
Here, we present a new stereoselective alkylation of titanium(IV) enolates of chiral N-acyl oxazolidinones with tert-butyl peresters from Cα-branched aliphatic carboxylic acids, which proceeds through the decarboxylation of the peresters and the subsequent formation of alkyl radicals to produce the alkylated adducts with an excellent diastereoselectivity. Theoretical calculations account for the observed reactivity and the outstanding stereocontrol. Importantly, the resultant compounds can be easily converted into ligands for asymmetric and catalytic transformations.
Stereoselective Oxidation of Titanium(IV) Enolates with Oxygen
Gómez-Palomino, Alejandro,Romea, Pedro,Urpí, Fèlix
, p. 2721 - 2726 (2018/06/08)
A novel approach to synthesize enantiomerically pure α-hydroxy carboxylic derivatives is reported. A highly stereoselective oxidation of titanium(IV) enolates from chiral N -acyloxazolidinones is performed with oxygen under simple experimental conditions
General and stereoselective aminoxylation of biradical titanium(iv) enolates with TEMPO: A detailed study on the effect of the chiral auxiliary
Kennington, Stuart C. D.,Gómez-Palomino, Alejandro,Salomó, Ernest,Romea, Pedro,Urpí, Fèlix,Font-Bardia, Mercè
, p. 4807 - 4815 (2018/07/13)
A comprehensive analysis of the influence of the chiral auxiliary on the α-aminoxylation of titanium(iv) enolates with TEMPO indicated that (S) 4-tert-butyl-1-oxazolidine-2-thione is the most appropriate scaffold to provide a single diastereomer in high yields for a variety of substrates, which converts such a radical reaction into a highly chemo- and stereoselective oxidation.
Asymmetric radical addition of TEMPO to titanium enolates
Mabe, Phillip J.,Zakarian, Armen
, p. 516 - 519 (2014/04/03)
A mild method for a-hydroxylation of N-acyl oxazolidinones by asymmetric radical addition of the 2,2,6,6-tetramethylpiperidine N-oxy (TEMPO) radical to titanium enolates was developed. The high diastereoselectivity and broad scope of the reaction show synthetic utility for the a-hydroxylation of substrates that are not tolerant to strongly basic conditions.
Diastereoselective synthesis of β-heteroaryl syn -α-methyl- β-amino acid derivatives via a double chiral auxiliary approach
Bian, Jianwei,Blakemore, David,Warmus, Joseph S.,Sun, Jianmin,Corbett, Matthew,Rose, Colin R.,Bechle, Bruce M.
supporting information, p. 562 - 565 (2013/03/29)
The addition of the SuperQuat enolate to five- and six-membered heterocyclic tert-butyl sulfinimines led to a high syn-selectivity of up to 99:1 in good to excellent yields. The reaction is tentatively proposed to proceed through an open-chain transition
A simple method for asymmetric trifluoromethylation of N-acyl oxazolidinones via Ru-catalyzed radical addition to zirconium enolates
Herrmann, Aaron T.,Smith, Lindsay L.,Zakarian, Armen
, p. 6976 - 6979 (2012/06/15)
A Ru-catalyzed direct thermal trifluoromethylation and perfluoroalkylation of N-acyloxazolidinones has been developed. The reaction is experimentally simple and requires inexpensive reagents while providing good yields of products with good levels of stereocontrol. Preliminary studies have shown notable compatibility with functional groups, aromatics, and certain heteroaromatic substituents. The described method provides a useful alternative for the synthesis of fluorinated materials in an experimentally convenient manner.
Dihydroxylation-based approach for the asymmetric syntheses of hydroxy-γ-butyrolactones
Peed, Jennifer,Davies, Iwan R.,Peacock, Lucy R.,Taylor, James E.,Kociok-Koehn, Gabriele,Bull, Steven D.
experimental part, p. 543 - 555 (2012/02/04)
A method of preparing enantiopure hydroxy-γ-butyrolactones containing multiple contiguous stereocenters in high yield with good diastereoselectivity has been developed. Osmium tetroxide mediated dihydroxylation of a range of β-alkenyl-β-hydroxy-N-acyloxazolidin-2-ones results in formation of triols that undergo spontaneous intramolecular 5-exo-trig cyclization reactions to provide hydroxy-γ-butyrolactones. The stereochemistry of these hydroxy-γ-butyrolactones has been established using NOE spectroscopy, which revealed that 1-substituted, 1,1-disubstituted, (E)-1,2-disubstituted, (Z)-1,2-disubstituted, and 1,1,2-trisubstituted alkenes undergo dihydroxylation with anti-diastereoselectivity, while 1,2,2-trisubstituted systems afford syn-diastereoisomers. The synthetic utility of this methodology has been demonstrated for the asymmetric synthesis of the natural product 2-deoxy-d-ribonolactone. Published 2011 by the American Chemical Society.
Efficient total synthesis of dysidenin, dysidin, and barbamide
Ilardi, Elizabeth A.,Zakarian, Armen
supporting information; experimental part, p. 2260 - 2263 (2012/06/30)
The total syntheses of three trichloroleucine-derived marine natural products-dysidenin, dysidin, and barbamide-capitalized on a practical and highly diastereoselective ruthenium catalyzed radical chloroalkylation of N-acyloxazolidinones as the key step. Copyright
Asymmetric synthesis of chiral δ-lactones containing multiple contiguous stereocenters
Peed, Jennifer,Perinan Dominguez, Ignacio,Davies, Iwan R.,Cheeseman, Matt,Taylor, James E.,Kociok-Koehn, Gabriele,Bull, Steven D.
supporting information; experimental part, p. 3592 - 3595 (2011/09/21)
A versatile methodology for the asymmetric synthesis of chiral δ-lactones containing multiple contiguous stereocenters has been developed that relies on a series of Evans' aldol, hydroxyl-directed cyclopropanation, methanolysis, and Hg(II) mediated cyclopropane ring-opening reactions for stereocontrol.
An expedient asymmetric synthesis of N-protected (S, S)-2-aminomethyl-1- cyclopropanecarboxylic acid
Aitken, David J.,Bull, Steven D.,Davies, Iwan R.,Drouin, Ludovic,Ollivier, Jean,Peed, Jennifer
scheme or table, p. 2729 - 2732 (2010/12/24)
An enantioselective synthesis of a N-Boc-protected trans-cyclopropane γ-amino acid is reported. The key chiral aldehyde intermediate is prepared in enantiomerically pure form using a three-step aldol-cyclopropanation-retro- aldol protocol.