(R)-1-Phenylethylamine as chiral auxiliary in the diastereoselective synthesis of tetrahydro-β-carboline derivatives

2007 ◽  
Vol 85 (12) ◽  
pp. 1033-1036 ◽  
Author(s):  
Aleksandra Siwicka ◽  
Krystyna Wojtasiewicz ◽  
Andrzej Leniewski ◽  
Jan K Maurin ◽  
Anna Zawadzka ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Asymmetric Synthesis ◽  
Indole Alkaloids ◽  
Chiral Auxiliary ◽  
Diastereoselective Synthesis

Modified sodium borohydrides were used in the reduction of the imine moiety in compounds containing the (R)-1-arylethylamine motif as a chiral auxiliary. Diastereomeric products were formed with moderate to good stereoselectivity and were effectively separated by column chromatography.Key words: asymmetric synthesis, indole alkaloids, hydrogen bond.

Indium Bromide-catalyzed Unprecedented Hydrogenolysis: A Novel One-Pot Synthesis of Per-O-Acetylated β-carboxymethyl O and S-glycosides

2020 ◽  
Vol 24 (8) ◽  
pp. 900-908
Author(s):  
Ram Naresh Yadav ◽  
Amrendra K Singh ◽  
Bimal Banik
Keyword(s):  
Asymmetric Synthesis ◽  
Chiral Auxiliary ◽  
Bioactive Molecules ◽  
One Pot ◽  
Enantiomerically Pure ◽  
Stereoselective Glycosylation ◽  
One Pot Synthesis ◽  
Wide Range

Numerous O (oxa)- and S (thia)-glycosyl esters and their analogous glycosyl acids have been accomplished through stereoselective glycosylation of various peracetylated bromo sugar with benzyl glycolate using InBr3 as a glycosyl promotor followed by in situ hydrogenolysis of resulting glycosyl ester. A tandem glycosylating and hydrogenolytic activity of InBr3 has been successfully investigated in a one-pot procedure. The resulting synthetically valuable and virtually unexplored class of β-CMGL (glycosyl acids) could serve as an excellent potential chiral auxiliary in the asymmetric synthesis of a wide range of enantiomerically pure medicinally prevalent β-lactams and other bioactive molecules of diverse medicinal interest.

Asymmetric Synthesis of Iridoid Derivatives Using Resolved 2-Phenylindoline as a Chiral Auxiliary

2008 ◽  
Vol 2008 (35) ◽  
pp. 5915-5921 ◽  
Author(s):  
Ellen M. Santangelo ◽  
Ilme Liblikas ◽  
Anoma Mudalige ◽  
Karl W. Törnroos ◽  
Per-Ola Norrby ◽  
...  
Keyword(s):  
Asymmetric Synthesis ◽  
Chiral Auxiliary

Diastereoselective Synthesis of (3R,5R)-γ-Hydroxypiperazic Acid

Synlett ◽  
2021 ◽  
Author(s):  
Juan R. Del Valle ◽  
Taylor A. Gerrein ◽  
Yassin M. Elbatrawi
Keyword(s):  
Asymmetric Synthesis ◽  
Late Stage ◽  
Ring Formation ◽  
Peptide Chain ◽  
Nonribosomal Peptides ◽  
Diastereoselective Synthesis ◽  
Hydroxylation Reaction ◽  
Enolate Hydroxylation

AbstractWe report an asymmetric synthesis of the (3R,5R)-γ-hydroxypiperazic acid (γ-OHPiz) residue encountered in several bioactive nonribosomal peptides. Our strategy relies on a diastereoselective enolate hydroxylation reaction and electrophilic N-amination to provide the acyclic γ-OHPiz precursor. This orthogonally protected α-hydrazino acid intermediate is amenable to late-stage diazinane ring formation following incorporation into a peptide chain. We determined the N-terminal amide rotamer propensity of the γ-OHPiz residue and showed that the γ-OH substituent enhances trans-amide bias relative to piperazic acid.

scholarly journals Asymmetric synthesis of the C1–C6 portion of the psymberin using an Evans chiral auxiliary

2013 ◽  
Vol 54 (41) ◽  
pp. 5555-5557 ◽  
Author(s):  
Ashutosh Pal ◽  
Zhenghong Peng ◽  
Paul T. Schuber ◽  
Basvoju A. Bhanu Prasad ◽  
William G. Bornmann
Keyword(s):  
Asymmetric Synthesis ◽  
Chiral Auxiliary
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