Preparation of 2,4-Disubstituted Cyclopentenones by Enantioselective Iridium-Catalyzed Allylic Alkylation: Synthesis of 2′-Methylcarbovir and<i>TEI-9826</i>
作者:Pierre Dübon、Mathias Schelwies、Günter Helmchen
DOI:10.1002/chem.200800495
日期:2008.7.28
A broadly applicable synthesis of chiral 2- or 2,4-substituted cyclopent-2-enones has been developed by combining asymmetric iridium-catalyzedallylic alkylation reactions and ruthenium-catalyzed ring-closing metathesis. Enantiomeric excesses (ee values) in the range of 95-99 % ee have been achieved. This method offers a straightforward access to biologically active prostaglandins of the PGA type.
<i>O</i>-Monoacyltartaric Acid Catalyzed Enantioselective Conjugate Addition of a Boronic Acid to Dienones: Application to the Synthesis of Optically Active Cyclopentenones
作者:Masaharu Sugiura、Ryo Kinoshita、Makoto Nakajima
DOI:10.1021/ol502526y
日期:2014.10.3
Enantioselective conjugateaddition of styrylboronic acid to dienones was effectively catalyzed by an O-monoacyltartaric acid to afford monostyrylated products with good enantioselectivity. The RCM of the monostyrylated products using the Hoveyda–Grubbs II catalyst afforded optically active cyclopentenones, including a synthetic intermediate of the antitumor agent TEI-9826. The study shows that a diene
Enantioselective Synthesis of γ‐Functionalized Cyclopentenones and δ‐Functionalized Cycloheptenones Utilizing a Redox‐Relay Heck Strategy
作者:Qianjia Yuan、Matthew B. Prater、Matthew S. Sigman
DOI:10.1002/adsc.201901239
日期:2020.1.23
In this report, the desymmetrization of cyclic enones under relay Heck conditions with an array of aryl boronic acids, alkenyl triflates and indole derivatives is described. This method grants facile access to diverse γ‐functionalized cyclopentenones and δ‐functionalized cycloheptenones. Using this approach, a formal synthesis of (S)‐baclofen was completed in high yield and excellent enantioselectivity
Enantioselective Modular Synthesis of 2,4-Disubstituted Cyclopentenones by Iridium-Catalyzed Allylic Alkylation
作者:Mathias Schelwies、Pierre Dübon、Günter Helmchen
DOI:10.1002/anie.200503945
日期:2006.4.3
Morpholine Ketene Aminal as Amide Enolate Surrogate in Iridium‐Catalyzed Asymmetric Allylic Alkylation
作者:Yeshua Sempere、Jan L. Alfke、Simon L. Rössler、Erick M. Carreira
DOI:10.1002/anie.201903090
日期:2019.7.8
Morpholine ketene aminal is employed in iridium‐catalyzed asymmetric allylic alkylation reactions as a surrogate for amide enolates to prepare γ,δ‐unsaturated β‐substituted morpholine amides. Kinetic resolution or, alternatively, stereospecific substitution affords the corresponding products in high enantiomeric excess. The utility of the products generated by this method has been showcased by their