120686-18-2Relevant articles and documents
Enantioselective Synthesis of β-Amino Acid Derivatives Enabled by Ligand-Controlled Reversal of Hydrocupration Regiochemistry
Buchwald, Stephen L.,Guo, Sheng,Zhu, Jiaqi
supporting information, p. 20841 - 20845 (2020/09/16)
A Cu-catalyzed enantioselective hydroamination of α,β-unsaturated carbonyl compounds for the synthesis of β-amino acid derivatives was achieved through ligand-controlled reversal of the hydrocupration regioselectivity. While the hydrocupration of α,β-unsaturated carbonyl compounds to form α-cuprated species has been extensively investigated, we report herein that, in the presence of an appropriate ancillary chiral ligand, the opposite regiochemistry can be observed for cinnamic acid derivatives, leading to the delivery of the copper to the β-position. This copper can react with an electrophilic aminating reagent, 1,2-benzisoxazole, to provide enantioenriched β-amino acid derivatives, which are important building blocks for the synthesis of natural products and bioactive small molecules.
Acylation of β-Amino Esters and Hydrolysis of β-Amido Esters: Candida antarctica Lipase A as a Chemoselective Deprotection Catalyst
M?enp??, Harri,Kanerva, Liisa T.,Liljeblad, Arto
, p. 1226 - 1232 (2016/04/05)
N-Acylation by lipase A from Candida antarctica (CAL-A) in ethyl butanoate was applied to the kinetic resolution of tert-butyl esters of 3-amino-3-phenylpropanoic acid (E>100), 3-amino-4-methylpentanoic acid (E>100) and 3-aminobutanoic acid (E=60) on 1.0-2.0 m scale. With the N-acylated resolution products, the exceptional ability of CAL-A to hydrolyse amides and bulky tert-butyl esters was then studied. In all N-acylated tert-butyl esters, chemoselectivity favoured the amide bond cleavage. The tert-butyl ester bond was left intact with 3-amino-3-phenylpropanoate, whereas with 3-amino-4-methylpentanoate and 3-aminobutanoate the CAL-A-catalysed hydrolysis of tert-butyl ester followed the amide hydrolysis.
Enantiopure 3-Amino-Substituted 1-Indanones, 1-Tetralones, and 1-Benzosuberones via Friedel-Crafts Cyclisation of ω-Aryl-β-benzamido Acids
Davies, Stephen G.,Goddard, Euan C.,Roberts, Paul M.,Russell, Angela J.,Thomson, James E.
, p. 1541 - 1544 (2015/06/30)
Conjugate addition of enantiopure lithium (R)-N-benzyl-N-(α-methylbenzyl)amide to a range of ω-aryl-α,β-unsaturated esters gives the corresponding ω-aryl-β-amino esters as single diastereoisomers in high yields. Friedel-Crafts cyclisation of the pendant c
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.
Scalable scny BRAnthesis of β-amino esters via reformatskcny BRA reaction with N-tert-butanesulfincny BRAl imines
Brinner, Kristin,Doughan, Brandon,Poon, Daniel J.
experimental part, p. 991 - 993 (2009/10/10)
The Reformatskcny BRA reagents derived from ethcny BRAl bromoacetate and tert-butcny BRAl bromoacetate add cleanlcny BRA, in high cny BRAield, and with good diastereoselectivitcny BRA to N-tert-butanesulfincny BRAl aldimines and ketimines. Importantlcny BRA, this reaction scales well (>50 mmol), and affords products upwards of 70% cny BRAield over three steps, starting from commerciallcny BRA available N-tert-butanesulfinamide, aldehcny BRAdes, and ketones.
Solid phase synthesis of novel α/β-tetrapeptides, electrospray ionization mass spectrometric evaluation of their metal cation complexation behavior, and conformational analysis using density functional theory (DFT)
Bandala, Yamir,Avina, Judit,Gonzalez, Tania,Rivero, Ignacio A.,Juaristi, Eusebio
, p. 349 - 358 (2008/12/20)
Thirty-four novel α/β-tetrapeptides (1-34) have been prepared employing solid-phase and in-parallel synthetic protocols. α/β- Tetrapeptides 1-34 were prepared by a combination of three α-amino acid residues (alanine (Ala), phenylalanine (Phe), and isoleucine (Ile)) with one β-amino acid residue (β3-homophenylglycine). The corresponding complexes of several selected α/β-tetrapeptides with alkali, alkaline earth, and transition metals, [tP + M+], were evaluated using ion electrospray-ionization mass spectrometry (ESI-MS). According to the results from analysis of mixtures, we can conclude that the position of the β-amino acid is determinant in the affinity toward different metal cations. Computational modeling (DFT, B3LYP 6-311++G) provided useful information regarding the most likely coordination sites of the metal ions on the receptor α/β-tetrapeptide 12, HO2C-α- Phe-α-Phe-α-Ile-β3-hPhg-NH2, as well as the conformational changes induced by the metal upon [tP + M+] complex formation. Copyright
Asymmetric michael addition of a recyclable chiral amine: Inversion of stereoselectivity caused by the difference of ethereal solvents
Node, Manabu,Hashimoto, Daisuke,Katoh, Takahiro,Ochi, Shunsuke,Ozeki, Minoru,Watanabe, Tsunefumi,Kajimoto, Tetsuya
supporting information; experimental part, p. 2653 - 2656 (2009/05/27)
(Chemical Equation Presented) The Michael addition of a chiral amine [(-)-6] to α,β-unsaturated esters (4) was attained and the stereoselectivity was inverted by changing the solvent from diethyl ether to tetrahydrofuran when α,β-unsaturated esters having an aromatic ring at the β-position were employed. In addition, the chiral auxiliary in the Michael adducts (9A) was facilely removed with N-iodosuccinimide to afford β-amino esters (10A) and 2-methoxy-d-bornylaldehyde (11), which can be reclaimed to the chiral amine (6) by reductive amination.
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.
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.
A novel synthesis of the macrocyclic spermidine alkaloid (+)-(S)-dihydroperiphylline
Sergeyev, Sergey A.,Hesse, Manfred
, p. 161 - 167 (2007/10/03)
A novel, short, and highly stereoselective synthesis of the macrocyclic spermidine alkaloid (+)-(S)-dihydroperiphylline (15) is described. The key synthetic steps were the stereoselective addition of the chiral amine 1 to the cinnamate 2 and cyclization o
