118040-79-2Relevant academic research and scientific papers
Iterative asymmetric allylic substitutions: Syn- and anti-1,2-diols through catalyst control
Park, Jin Kyoon,McQuade, D. Tyler
supporting information; experimental part, p. 2717 - 2721 (2012/04/17)
A copper-catalyzed asymmetric allylic boronation (AAB) gives access to syn- and anti-1,2-diols. The method facilitates an iterative strategy for the preparation of polyols (see scheme), such as the fully differentiated L-ribo-tetrol and protected D-arabin
Enantioselective synthesis of allylboronates bearing a tertiary or quaternary B-substituted stereogenic carbon by NHC-Cu-catalyzed substitution reactions
Guzman-Martinez, Aikomari,Hoveyda, Amir H.
supporting information; experimental part, p. 10634 - 10637 (2010/11/05)
Allylic substitutions that afford α-substituted allylboronates bearing B-substituted tertiary or quaternary carbon stereogenic centers are presented. C-B bond-forming reactions, catalyzed by chiral bidentate Cu-NHC complexes, are performed in the presence of commercially available bis(pinacolato)diboron. Transformations proceed in high yield (up to >98%) and site selectivity (>98% SN2′), and in up to >99:1 enantiomer ratio. Trans- or cis-disubstituted alkenes can be used; alkyl- (linear as well as branched) and aryl-trisubstituted allylic carbonates serve as effective substrates. Allylboronates that bear a quaternary carbon center are air-stable and can be easily purified by silica gel chromatography; in contrast, secondary allylboronates cannot be purified in the same manner and are significantly less stable. Oxidation of the enantiomerically enriched products furnishes secondary or tertiary allylic alcohols, valuable small molecules that cannot be easily obtained in high enantiomeric purity by alternative synthesis or kinetic resolution approaches.
Allylation of nitrosobenzene with pinacol allylboronates. A regioselective complement to peroxide oxidation
Kyne, Robert E.,Ryan, Michael C.,Kliman, Laura T.,Morken, James P.
supporting information; experimental part, p. 3796 - 3799 (2010/10/21)
Addition of nitrosobenzene to pinacol allylboronates leads to oxidation of the organoboron with concomitant rearrangement of the substrate alkene. This reaction appears to proceed by allylboration of the nitroso group in analogy to carbonyl and imine allylation reactions. Remarkably, the N-O bond is cleaved during the reaction such that simple alcohols are the final reaction product.
Processes for the preparation of 5-amino-4-hydroxyvaleric acid derivatives
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, (2008/06/13)
The invention relates to novel processes and intermediates for the preparation of 5-amino-4-hydroxyvaleric acid derivatives of the formula STR1 in which R1 represents hydrogen, optionally substituted alkyl, cycloalkyl, cycloalkyl-lower alkyl, a
A Versatile and Stereocontrolled Synthesis of Hydroxyethylene Dipeptide Isosteres
Herold, Peter,Duthaler, Rudolph,Rihs, Grety,Angst, Christof
, p. 1178 - 1185 (2007/10/02)
An asymmetric synthesis of the hydroxyethylene dipeptide isostere unit 1 is described.The synthesis provides excellent stereocontrol over all three chiral centers and is amenable to variation of substituents R1 and R2.Key intermediat
AN EFFICIENT SYNTHESIS OF THE γ-LACTONE CORRESPONDING TO A HYDROXYETHYLENE DIPEPTIDE ISOSTERE USING STEREOSELECTIVE BROMOLACTONISATION OF A CHIRAL ACYLOXAZOLIDINONE
Bradbury, Robert H.,Revill, John M.,Rivett, Janet E.,Waterson, David
, p. 3845 - 3848 (2007/10/02)
An efficient synthetic route is described to the γ-lactone 11 corresponding to the dipeptide isostere (2S,4S,5S)-5-amino-6-cyclohexyl-4-hydroxy-2-isopropylhexanoic acid, in which stereochemical control is achieved by participation of chiral acyloxazolidinone 6 in a stereoselective bromolactonisation reaction.
