164660-17-7Relevant academic research and scientific papers
Asymmetric synthesis of cyclic β-amino acids and cyclic amines via sequential diastereoselective conjugate addition and ring closing metathesis
Chippindale, Ann M.,Davies, Stephen G.,Iwamoto, Keiji,Parkin, Richard M.,Smethurst, Christian A. P.,Smith, Andrew D.,Rodriguez-Solla, Humberto
, p. 3253 - 3265 (2007/10/03)
Diastereoselective conjugate addition of lithium (S)-N-allyl-N-α-methylbenzylamide to a range of α,β-unsaturated esters followed by ring closing metathesis is used to afford efficiently a range of substituted cyclic β-amino esters in high d.e. Alternatively, conjugate addition to α,β-unsaturated Weinreb amides, functional group conversion and ring closing metathesis affords cyclic amines in high d.e. The further application of this methodology to the synthesis of a range of carbocyclic β-amino esters via conjugate addition, enolate alkylation and ring closing metathesis is also described. Application of this methodology affords, after deprotection, (S)-homoproline, (S)-homopipecolic acid, (S)-coniine and (1S,2S)-trans-pentacin.
Ring closing metathesis for the asymmetric synthesis of (S)-homopipecolic acid, (S)-homoproline and (S)-coniine
Davies, Stephen G.,Iwamoto, Keiji,Smethurst, Christian A. P.,Smith, Andrew D.,Rodriguez-Solla, Humberto
, p. 1146 - 1148 (2007/10/03)
Diastereoselective conjugate addition of lithium (S)-N-allyl-N-α-methylbenzylamide to α,β-unsaturated esters or Weinreb amides, followed by ring closing metathesis is used to afford the cyclic β-amino acids (S)-homopipecolic acid and (S)-homoproline and the amine (S)-coniine in high ee.
The use of lithium (α-methylbenzyl)allylamide for the asymmetric synthesis of unsaturated β-amino acid derivatives
Davies, Stephen G.,Fenwick, David R.,Ichihara, Osamu
, p. 3387 - 3391 (2007/10/03)
The unsaturated β-amino acid derivatives (3R)-(E)-3-(N-tert- butoxycarbonyl)aminohex-4-enoate and methyl (2S,3S)-3-(N-tert- butoxycarbonyl)-amino-2-bydroxyhex-4-enoate have been synthesised from lithium (s)-(α-methylbenzyl)allylamide and (E,E)-tert-butyl hex-2,4- dienoate. After a highly stereoselective conjugate addition of the lithium amide to the α,β-unsaturated ester, or a highly stereoselective conjugate addition-electrophilic hydroxylation, the adducts are deallylated and the resulting secondary amines converted to either a benzoyl amide or oxazolidinone. The N-α-methylbenzyl group is then removed with either formic acid or using a dissolving metal reduction. These deprotection procedures leave unsaturation in the molecules intact.
Lithium (α-Methylbenzyl)allylamide: A Differentially Protected Chiral Ammonia Equivalent for the Asymmetric Synthesis of β-Amino Acids and β-Lactams
Davies, Stephen G.,Fenwick, David R.
, p. 1109 - 1110 (2007/10/02)
The addition products from the highly stereoselective conjugate additions of lithium (αS)-(α-methylbenzyl)allylamide to α,β-unsaturated tert-butyl esters are efficiently deallylated with tris(triphenylphosphine)rhodium(I) chloride and converted, after tra
