Resolution Of Racemic Allylic Alcohols Research Articles

Kinetic resolution of racemic allylic alcohols via iridium-catalyzed asymmetric hydrogenation: scope, synthetic applications and insight into the origin of selectivity.

Asymmetric hydrogenation is one of the most commonly used tools in organic synthesis, whereas, kinetic resolution via asymmetric hydrogenation is less developed. Herein, we describe the first iridium catalyzed kinetic resolution of a wide range of trisubstituted secondary and tertiary allylic alcohols. Large selectivity factors were observed in most cases (s up to 211), providing the unreacted starting materials in good yield with high levels of enantiopurity (ee up to >99%). The utility of this method is highlighted in the enantioselective formal synthesis of some bioactive natural products including pumiliotoxin A, inthomycin A and B. DFT studies and a selectivity model concerning the origin of selectivity are presented.

ChemInform Abstract: Kinetic Resolution of Racemic Allylic Alcohols by Catalytic Asymmetric Substitution of the OH Group with Monosubstituted Hydrazines.

A new strategy has been established for the kinetic resolution of racemic allylic alcohols through a palladium/sulfonyl-hydrazide-catalyzed asymmetric OH-substitution under mild conditions. In the presence of 1 mol % [Pd(allyl)Cl]2 , 4 mol % (S)-SegPhos, and 10 mol % 2,5-dichlorobenzenesulfonyl hydrazide, a range of racemic allylic alcohols were smoothly resolved with selectivity factors of more than 400 through an asymmetric allylic alkylation of monosubstituted hydrazines under air at room temperature. Importantly, this kinetic resolution process provided various allylic alcohols and allylic hydrazine derivatives with high enantiopurity.

Kinetic Resolution of Racemic Allylic Alcohols by Catalytic Asymmetric Substitution of the OH Group with Monosubstituted Hydrazines.

A new strategy has been established for the kinetic resolution of racemic allylic alcohols through a palladium/sulfonyl-hydrazide-catalyzed asymmetric OH-substitution under mild conditions. In the presence of 1 mol % [Pd(allyl)Cl]2 , 4 mol % (S)-SegPhos, and 10 mol % 2,5-dichlorobenzenesulfonyl hydrazide, a range of racemic allylic alcohols were smoothly resolved with selectivity factors of more than 400 through an asymmetric allylic alkylation of monosubstituted hydrazines under air at room temperature. Importantly, this kinetic resolution process provided various allylic alcohols and allylic hydrazine derivatives with high enantiopurity.

ChemInform Abstract: Dynamic Kinetic Resolution of Racemic Allylic Alcohols via Hydrolase—Metal Combo Catalysis: An Effective Method for the Synthesis of Optically Active Compounds

AbstractReview: [41 refs.

Dynamic Kinetic Resolution of Racemic Allylic Alcohols via Hydrolase–Metal Combo Catalysis: An Effective Method for the Synthesis of Optically Active Compounds

Abstract This review focuses on the dynamic kinetic resolution (DKR) of racemic allylic alcohols to produce allylic esters in high chemical and optical yields, which was achieved by combining hydrolase-catalyzed kinetic resolution and in situ racemization of the remaining less reactive enantiomers. Two classes of racemization catalysts, e.g., Ru complexes and oxovanadium compounds, are mainly discussed. Typical examples of DKR are shown along with their application in the concise syntheses of optically active compounds as valuable synthetic intermediates. The domino process integrating DKR with the active use of the installed acyl moiety for subsequent intramolecular cyclization is also discussed, which has great potential for the asymmetric syntheses of optically active fused cyclic molecules possessing multiple stereogenic centers.

Ruthenium‐Catalyzed Regio‐ and Enantioselective Allylic Substitution with Water: Direct Synthesis of Chiral Allylic Alcohols

Enantioselective allylic substitution catalyzed by transitionmetal complexes is an important process in organic synthesis. For many years, mainly palladium complexes that contain chiral ligands have been employed as efficient catalysts in these reactions. Recent studies have demonstrated that chiral catalysts based on other transition metals show different regioselectivity in the synthesis of branched allylic products via monosubstituted p-allyl intermediates. Although a variety of carbon and nitrogen nucleophiles can be used in those reactions, applicable oxygen nucleophiles are still limited to phenols and alcohols, which produce allylic ethers. Thus, enantioenriched branched allylic alcohols, which serve as useful chiral building blocks, are often synthesized by other processes, such as the hydrogenation of a,b-unsaturated ketones, the nucleophilic addition of vinylmetal reagents to aldehydes and ketones, and the kinetic resolution of racemic allylic alcohols. Recently, new ways to access these compounds have been developed, and they involve allylic substitution by a two-step conversion involving allylic esters and silyl ethers (Scheme 1; OPG= ester or silyl

Kinetic resolution of allylic alcohols using a chiral phosphine catalyst.

[reaction: see text] The kinetic resolution of racemic allylic alcohols 3, 6, and 12--17 has been explored using the PBO catalyst 7 for activation of isobutyric anhydride. Trisubstituted allylic alcohols (12--15; 17) are the best substrates and react with an enantioselectivity of s = 32--82 at -40 degrees C.

Kinetic resolution of racemic allylic alcohols by BINAP-ruthenium(II) catalyzed hydrogenation

Dedoublement optique d'alcools allyliques aliphatiques ou monocycliques comme le cyclohexene-2ol ou le methyl-2 nonene-2 ol-4

Kinetic resolution of racemic allylic alcohols by enantioselective epoxidation. A route to substances of absolute enantiomeric purity?

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetic resolution of racemic allylic alcohols by enantioselective epoxidation. A route to substances of absolute enantiomeric purity?Victor S. Martin, Scott S. Woodard, Tsutomu Katsuki, Yasuhiro Yamada, Masonari Ikeda, and K. Barry SharplessCite this: J. Am. Chem. Soc. 1981, 103, 20, 6237–6240Publication Date (Print):October 1, 1981Publication History Published online1 May 2002Published inissue 1 October 1981https://doi.org/10.1021/ja00410a053RIGHTS & PERMISSIONSArticle Views6412Altmetric-Citations694LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (573 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts