Highly Enantioselective and Practical Cinchona‐Derived Phase‐Transfer Catalysts for the Synthesis of α‐Amino Acids.

Park, Hyeung‐geun; Jeong, Byeong‐Seon; Yoo, Mi‐Sook; Lee, Jeong‐Hee; Park, Mi‐kyoung; Lee, Yeon‐Ju; Kim, Mi‐Jeong; Jew, Sang‐sup

doi:10.1002/chin.200251186

Cited by 6 publications

(11 citation statements)

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“…The amino acids used were either commercially available or prepared following established procedures 15. See for full experimental data on the synthesis of the compounds the Supporting Information (SI).…”

Section: Resultsmentioning

confidence: 99%

Incorporation of Fluorinated Phenylalanine Generates Highly Specific Inhibitor of Proteasome’s Chymotrypsin-like Sites

et al. 2010

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Proteasomal processing is conducted by three individual catalytic subunits, namely β1, β2, and β5. Subunit-specific inhibitors are useful tools in dissecting the role of these individual subunits and are leads toward the development of antitumor agents. We here report that the presence of fluorinated phenylalanine derivatives in peptide based proteasome inhibitors has a profound effect on inhibitor potency and selectivity. Specifically, compound 4a emerges as one of the most β5 specific inhibitors known to date.

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Section: Resultsmentioning

confidence: 99%

Incorporation of Fluorinated Phenylalanine Generates Highly Specific Inhibitor of Proteasome’s Chymotrypsin-like Sites

et al. 2010

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“…The appropriate reactive halides were obtained from dimethylnaphthalenes through radical bromination with NBS (88 % yield for 2,7-derivative). Reaction of the dibromides with 2.03 equiv of dihydrocinchonidine and dihydrocinchonine and subsequent 9 -allylation gave the respective dimers 170b – 175b in 90–95 % yield [ 114 ]. Further expansion of the ring system was done by the Najera group, who introduced a 9,10-dimethylanthracenyl linker [ 115 ].…”

Section: N1-qarternary Ammonium Saltsmentioning

confidence: 99%

“…Study of analogues of CD-153 revealed that 2-fluorine atom in the xylylene linker as well as 10,11-hydrogenated alkaloid unit further improved the enantioselectivity [ 112 ]. A highly hindered trimer CD-196b provided high enantioselectivity at a cost of reactivity [ 128 ] The second generation Park’s catalyst DHCD-170b with 2,7-naphthyl link was one of the most efficient and enantioselective catalysts for the benzylation of glycine imine under PTC conditions providing 97 %ee at and 1 %mol loading [ 114 ]. This catalyst is commercially available and can be acquired from major reagent suppliers (Fig.…”

Section: N1-qarternary Ammonium Saltsmentioning

confidence: 99%

Dimeric Cinchona alkaloids

Boratyński

2015

Mol Divers

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Nature is full of dimeric alkaloids of various types from many plant families, some of them with interesting biological properties. However, dimeric Cinchona alkaloids were not isolated from any species but were products of designed partial chemical synthesis. Although the Cinchona bark is amongst the sources of oldest efficient medicines, the synthetic dimers found most use in the field of asymmetric synthesis. Prominent examples include the Sharpless dihydroxylation and aminohydroxylation ligands, and dimeric phase transfer catalysts. In this article the syntheses of Cinchona alkaloid dimers and oligomers are reviewed, and their structure and applications are outlined. Various synthetic routes exploit reactivity of the alkaloids at the central 9-hydroxyl group, quinuclidine, and quinoline rings, as well as 3-vinyl group. This availability of reactive sites, in combination with a plethora of linker molecules, contributes to the diversity of the products obtained.

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“…Inspired with the interesting result from the PTC-assisted INOC, we intensively examined other PTC catalysts [ 27 ] for improved selectivity, as summarized in Scheme 5 . Although other PTCs seemed not to influence much the facial selectivity of INOC, potential chiral induction by PTC in INOC was observed.…”

Section: Resultsmentioning

confidence: 99%

Synthetic Studies on Bioactive Natural Polyketides: Intramolecular Nitrile Oxide-Olefin Cycloaddition Approach for Construction of a Macrolactone Skeleton of Macrosphelide B

Paek

Suh

2011

Molecules

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Studies on the synthesis of macrosphelide B via an intramolecular nitrile oxide-olefin cycloaddition (INOC) is described. In particular, an asymmetric INOC approach using phase transfer catalysts seems to be a potentially efficient and versatile procedure for the construction of the macrolactone skeleton of macrosphelide B in terms of facial selectivity. Our preliminary and unprecedented stereoselective procedure is anticipated to be usefully applied through further studies for the synthesis of the macrosphelide family.

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Highly Enantioselective and Practical Cinchona‐Derived Phase‐Transfer Catalysts for the Synthesis of α‐Amino Acids.

Abstract: For Abstract see ChemInform Abstract in Full Text.

Cited by 6 publications

References 1 publication

Incorporation of Fluorinated Phenylalanine Generates Highly Specific Inhibitor of Proteasome’s Chymotrypsin-like Sites

Incorporation of Fluorinated Phenylalanine Generates Highly Specific Inhibitor of Proteasome’s Chymotrypsin-like Sites

Dimeric Cinchona alkaloids

Synthetic Studies on Bioactive Natural Polyketides: Intramolecular Nitrile Oxide-Olefin Cycloaddition Approach for Construction of a Macrolactone Skeleton of Macrosphelide B

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