265669-72-5Relevant academic research and scientific papers
Diastereoselective Ireland-Claisen rearrangements of substituted allyl β-amino esters: Applications in the asymmetric synthesis of C(5)-substituted transpentacins
Davies, Stephen G.,Fletcher, Ai M.,Lee, James A.,Roberts, Paul M.,Souleymanou, Myriam Y.,Thomson, James E.,Zammit, Charlotte M.
, p. 2702 - 2728 (2014/05/06)
The diastereoselective Ireland-Claisen rearrangement of a range of substituted allyl β-amino esters gave the corresponding enantiopure α-substituted-β-amino esters with good diastereoselectivity. The application of this methodology in the asymmetric synthesis of a range of C(5)-substituted 1,2-anti-1,5-syn-transpentacins was demonstrated by the rearrangement of a range of β-amino esters derived from sorbic acid, followed by esterification, ring-closing metathesis, hydrogenolytic deprotection/reduction, and hydrolysis, which gave the C(5)-substituted transpentacins in only 9 steps from commercially available starting materials. This journal is the Partner Organisations 2014.
Asymmetric synthesis of syn- and anti-α-deuterio-β3- phenylalanine derivatives
Davies, Stephen G.,Foster, Emma M.,McIntosh, Catherine R.,Roberts, Paul M.,Rosser, Timothy E.,Smith, Andrew D.,Thomson, James E.
experimental part, p. 1035 - 1050 (2011/10/04)
The conjugate addition of lithium (S)-N-benzyl-N-(α-methylbenzyl) amide to a range of aryl substituted tert-butyl cinnamate esters followed by reaction of the resultant lithium β-amino enolates with D2O provides access to anti configured α-deut
Double asymmetric induction as a mechanistic probe: The doubly diastereoselective conjugate addition of enantiopure lithium amides to enantiopure α,β-unsaturated esters and enantiopure α,β-unsaturated hydroxamates
Davies, Stephen G.,Lee, James A.,Roberts, Paul M.,Thomson, James E.,Yin, Jingda
experimental part, p. 6382 - 6403 (2011/09/19)
The doubly diastereoselective conjugate addition of the antipodes of lithium N-benzyl-N-(α-methylbenzyl)amide to a range of enantiopure α,β-unsaturated esters [derived from Corey's 8-phenylmenthol chiral auxiliary] and enantiopure α,β-unsaturated hydroxamates [derived from our 'chiral Weinreb amide' auxiliary (S)-N-1-(1′-naphthyl)ethyl-O-tert- butylhydroxylamine] has been used as a mechanistic probe to determine the reactive conformations of these acceptors.
Enantioselective synthesis of α-fluoro-β3-amino esters: Synthesis of enantiopure, orthogonally protected α-fluoro- β3-lysine
Duggan, Peter J.,Johnston, Martin,March, Taryn L.
experimental part, p. 7365 - 7372 (2011/02/23)
The scope of a tandem conjugate addition-fluorination sequence performed on α,β-unsaturated esters using the enantiopure lithium amide derived from (S)-N-benzyl-N-(α-methylbenzyl)amine, and the electrophilic fluorinating agent N-fluorobenzenesulfonimide h
Parallel synthesis of homochiral β-amino acids
Davies, Stephen G.,Mulvaney, Andrew W.,Russell, Angela J.,Smith, Andrew D.
, p. 1554 - 1566 (2008/02/09)
The parallel asymmetric synthesis of an array of 30 β-amino acids of high enantiomeric purity using the conjugate addition of homochiral lithium N-benzyl-N-(α-methylbenzyl)amide as the key step is accomplished. The experimental simplicity and highly practical nature of the protocol is demonstrated by the efficient parallel conversion of 15 α,β-unsaturated esters to both enantiomeric series of the corresponding β-amino acids in high overall yields and selectivities with minimal purification involved in each step of the reaction protocol.
Asymmetric three- and [2 + 1]-component conjugate addition reactions for the stereoselective synthesis of polysubstituted piperidinones
Davies, Stephen G.,Roberts, Paul M.,Smith, Andrew D.
, p. 1405 - 1415 (2008/02/10)
The efficiency and stereoselectivity of the conjugate addition of lithium (Z)- or (E)-β-amino ester enolates, generated by lithium amide conjugate addition to an α,β-unsaturated ester or deprotonation of a β-amino ester, respectively, to a range of α,β-unsaturated acceptors has been investigated. Deprotonation of a β-amino ester with LDA, followed by conjugate addition to a chiral α,β-unsaturated oxazolidinone gives high 2,3-anti selectivity (～90% d.e.), with hydrogenolysis and purification to homogeneity generating stereodefined trisubstituted piperidinones as single stereoisomers. Asymmetric three-component couplings of α,β-unsaturated esters and alkylidene malonates initiated by lithium amide conjugate addition proceeds with high levels of 2,3-anti stereoselectivity, with hydrogenolysis giving tetrasubstituted piperidinones. This journal is The Royal Society of Chemistry.
Homochiral lithium amides for the asymmetric synthesis of β-amino acids
Davies, Stephen G.,Garrido, Narciso M.,Kruchinin, Dennis,Ichihara, Osamu,Kotchie, Luke J.,Price, Paul D.,Mortimer, Anne J. Price,Russell, Angela J.,Smith, Andrew D.
, p. 1793 - 1811 (2007/10/03)
Secondary homochiral lithium amides derived from α-methylbenzylamine undergo highly diastereoselective conjugate additions to a range of α,β-unsaturated esters. The corresponding β-amino acids are readily liberated by successive N-debenzylation and ester hydrolysis, furnishing (R)-β-amino butyric acid, (R)-β-amino pentanoic acid, (S)-β-leucine, (R)-β-amino octanoic acid, (S)-β-phenylalanine, (S)-β-tyrosine methyl ether, (S)-β-tyrosine hydrochloride and (S)-β-(2-methoxyphenyl)-β-amino propanoic acid in high yields and high ee. The application of this procedure to the synthesis of the natural products (R)-β-DOPA and (R)-β-lysine is demonstrated. The development of a simplified one-pot reaction protocol applicable to the multi-gram scale synthesis of homochiral β-amino esters is also delineated.
Double asymmetric induction as a mechanistic probe: Conjugate addition for the asymmetric synthesis of a pseudotripeptide
Davies, Stephen G.,Hermann, Gesine J.,Sweet, Miles J.,Smith, Andrew D.
, p. 1128 - 1129 (2007/10/03)
Double asymmetric induction as a mechanistic probe indicates that, for the conjugate addition of (R)- and (S)-lithium N-benzyl-N-α-methylbenzylamide to (S)-3′-phenylprop-2′-enoyl-4-benzyloxazolidinone, the reactive conformation of the N-acyl oxazolidinone is the anti-s-cis form, facilitating the asymmetric synthesis of a pseudotripeptide.
Chemoselective debenzylation of N-benzyl tertiary amines with ceric ammonium nitrate
Bull, Steven D.,Davies, Stephen G.,Fenton, Carry,Mulvaney, Andrew W.,Shyam Prasad,Smith, Andrew D.
, p. 3765 - 3774 (2007/10/03)
Treatment of a range of N-benzyl tertiary amines with aqueous eerie ammonium nitrate results in N-debenzylation to afford the corresponding secondary amine. Chemoselective mono-W-debenzylation of N-benzyl tertiary amines is shown to occur in the presence of N-benzyl amides, O-benzyl ethers, O-benzyl esters, O-benzyl phenolates and 5-benzyl ethers. The Royal Society of Chemistry 2000.
