An effective<i>cis</i>-β-octahedral Mn(<scp>iii</scp>) SALPN catalyst for the Mukaiyama–Isayama hydration of α,β-unsaturated esters

Donnelly, Paul S.; North, Andrea J.; Radjah, Natalia Caren; Ricca, Michael; Robertson, Angus; White, Jonathan M.; Rizzacasa, Mark A.

doi:10.1039/c9cc03921j

“…Co(acac) 2 catalyzed oxygen mediated hydration failed to deliver the desired β‐hydroxy product. Of note, Rizzacasa and co‐workers previously demonstrated aerobic hydration of α,β‐unsaturated esters by using a designed Mn‐catalyst [47] . However, the sterically more hindered even more challenging α,α‐disubstituted systems as studied herein were not included in these investigations.…”

Section: Resultsmentioning

confidence: 97%

Fe‐Catalyzed Anaerobic Mukaiyama‐Type Hydration of Alkenes using Nitroarenes

Bhunia

¹

,

Bergander

²

,

Daniliuc

³

et al. 2021

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Hydration of alkenes using first row transition metals (Fe, Co,M n) under oxygen atmosphere (Mukaiyamatype hydration) is highly practical for alkene functionalization in complex synthesis.Different hydration protocols have been developed, however,c ontrol of the stereoselectivity remains ac hallenge.H erein, highly diastereoselective Fe-catalyzed anaerobic Markovnikov-selective hydration of alkenes using nitroarenes as oxygenation reagents is reported. The nitro moiety is not well explored in radical chemistry and nitroarenes are knownt os uppress free radical processes.O ur findings show the potential of cheap nitroarenes as oxygen donors in radical transformations.S econdary and tertiary alcohols were prepared with excellent Markovnikov-selectivity.T he method features large functional group tolerance and is also applicable for late-stage chemical functionalization. The anaerobic protocol outperforms existing hydration methodology in terms of reaction efficiency and selectivity. Scheme 1. Literature backgrounda nd suggestedp rocess.

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“…In 2019, the groups of Donnelly and Rizzacasa disclosed an enhanced hydration of α,β-unsaturated esters toward αhydroxy esters (compared to the previously mentioned work by Mukaiyama et al) 88 by the use of a Mn(III) complex with a Schiff base ligand (Mn-25, Figure 14). 93 Notably, the authors reported that the more reactive silane previously used by Shenvi (Ph(iPrO)SiH 2 ) 27 did not present a significant improvement for the reaction; therefore, the reaction conditions remained similar to Mukaiyama's report. Furthermore, they also found that the treatment with P(OEt) 3 was not necessary, as previously reported by Magnus, 89 suggesting that the hydroperoxides are not formed in significant amounts or that they could be reduced in situ by the silane in excess.…”

Section: Hydroarylationmentioning

confidence: 62%

Homogeneous Manganese-Catalyzed Hydrofunctionalizations of Alkenes and Alkynes: Catalytic and Mechanistic Tendencies

Torres-Calis

¹

,

Garcı́a

²

2022

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In recent years, many manganese-based homogeneous catalytic precursors have been developed as powerful alternatives in organic synthesis. Among these, the hydrofunctionalizations of unsaturated C–C bonds correspond to outstanding ways to afford compounds with more versatile functional groups, which are commonly used as building blocks in the production of fine chemicals and feedstock for the industrial field. Herein, we present an account of the Mn-catalyzed homogeneous hydrofunctionalizations of alkenes and alkynes with the main objective of finding catalytic and mechanistic tendencies that could serve as a platform for the works to come.

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“…Of note,R izzacasa and co-workers previously demonstrated aerobic hydration of a,b-unsaturated esters by using ad esigned Mn-catalyst. [47] However, the sterically more hindered even more challenging a,adisubstituted systems as studied herein were not included in these investigations.…”

Section: Forschungsartikelmentioning

confidence: 99%

Fe‐Catalyzed Anaerobic Mukaiyama‐Type Hydration of Alkenes using Nitroarenes

Bhunia

¹

,

Bergander

²

,

Daniliuc

³

et al. 2021

View full text Add to dashboard Cite

Hydration of alkenes using first row transition metals (Fe, Co,M n) under oxygen atmosphere (Mukaiyamatype hydration) is highly practical for alkene functionalization in complex synthesis.Different hydration protocols have been developed, however,c ontrol of the stereoselectivity remains ac hallenge.H erein, highly diastereoselective Fe-catalyzed anaerobic Markovnikov-selective hydration of alkenes using nitroarenes as oxygenation reagents is reported. The nitro moiety is not well explored in radical chemistry and nitroarenes are knownt os uppress free radical processes.O ur findings show the potential of cheap nitroarenes as oxygen donors in radical transformations.S econdary and tertiary alcohols were prepared with excellent Markovnikov-selectivity.T he method features large functional group tolerance and is also applicable for late-stage chemical functionalization. The anaerobic protocol outperforms existing hydration methodology in terms of reaction efficiency and selectivity. Scheme 1. Literature backgrounda nd suggestedp rocess.

show abstract

An effectivecis-β-octahedral Mn(iii) SALPN catalyst for the Mukaiyama–Isayama hydration of α,β-unsaturated esters

Abstract: Two cis-β-MnIIISALPN catalysts were synthesised and tested in the Mukaiyama–Isayama hydration of α,β-unsaturated esters.

Cited by 9 publications

References 15 publications

Fe‐Catalyzed Anaerobic Mukaiyama‐Type Hydration of Alkenes using Nitroarenes

Fe‐Catalyzed Anaerobic Mukaiyama‐Type Hydration of Alkenes using Nitroarenes

Homogeneous Manganese-Catalyzed Hydrofunctionalizations of Alkenes and Alkynes: Catalytic and Mechanistic Tendencies

Fe‐Catalyzed Anaerobic Mukaiyama‐Type Hydration of Alkenes using Nitroarenes

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