A Flexible Synthesis of Polypropionates via Diastereodivergent Reductive Ring‐Opening of Trisubstituted Secondary Glycidols DOI Creative Commons
Katharina Pieper,

Robin Bleith,

Christian Köhler

et al.

Angewandte Chemie, Journal Year: 2023, Volume and Issue: 136(9)

Published: Dec. 18, 2023

Abstract Polypropionates, characterized by their alternating sequence of stereocenters bearing methyl‐ and hydroxy‐groups, are structurally diverse natural products utmost importance. [1] Herein, we introduce a novel concept approach towards polypropionate synthesis featuring diastereodivergent reductive epoxide‐opening as key step. Readily available stereochemically uniform trisubstituted sec‐glycidols serve branching points for the highly selective all isomers building blocks with three or more consecutive stereocenters. Stereodiversification is accomplished an unprecedented mechanism‐control over complementary modification epoxide's tertiary C‐atom excellent control regio‐ stereoselectivity. Since our method not only suited preparation specific targets but also compound libraries, it will have great impact on synthesis.

Language: Английский

Stereoconvergent Approach to the Enantioselective Construction of α‐Quaternary Alcohols by Radical Epoxide Allylation DOI Creative Commons
Sebastian Höthker,

Annika Plato,

Stefan Grimme

et al.

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(29)

Published: April 26, 2024

Abstract We describe a highly stereoconvergent radical epoxide allylation towards diastereomerically and enantiomerically enriched α ‐quaternary alcohols in two steps from olefins. Our approach combines the stereospecifity enantioselectivity of Shi epoxidation with unprecedented Ti(III)‐promoted intramolecular group transfer epoxides. A directional isomerization step via configurationally labile intermediates enables selective preparation all‐carbon quaternary stereocenters unique fashion.

Language: Английский

Citations

3
Formal Anti‐Markovnikov Addition of Water to Olefins by Titanocene‐Catalyzed Epoxide Hydrosilylation: From Stoichiometric to Sustainable Catalytic Reactions DOI Creative Commons
Sebastian Höthker, Andreas Gansäuer

Global Challenges, Journal Year: 2023, Volume and Issue: 7(7)

Published: May 2, 2023

Abstract Here, the evolution of titanocene‐catalyzed hydrosilylation epoxides that yields corresponding anti‐Markovnikov alcohols is summarized. The study focuses on aspects sustainability, efficient catalyst activation, and stereoselectivity. latest variant reaction employs polymethylhydrosiloxane (PMHS), a waste product Müller–Rochow process as terminal reductant, features an activation with benzylMgBr use bench stable Cp 2 TiCl precatalyst. combination olefin epoxidation epoxide provides uniquely approach to formal addition H O olefins.

Language: Английский

Citations

8
Stereoconvergent Approach to the Enantioselective Construction of α‐Quaternary Alcohols by Radical Epoxide Allylation DOI Creative Commons
Sebastian Höthker,

Annika Plato,

Stefan Grimme

et al.

Angewandte Chemie, Journal Year: 2024, Volume and Issue: 136(29)

Published: April 26, 2024

Abstract We describe a highly stereoconvergent radical epoxide allylation towards diastereomerically and enantiomerically enriched α ‐quaternary alcohols in two steps from olefins. Our approach combines the stereospecifity enantioselectivity of Shi epoxidation with unprecedented Ti(III)‐promoted intramolecular group transfer epoxides. A directional isomerization step via configurationally labile intermediates enables selective preparation all‐carbon quaternary stereocenters unique fashion.

Language: Английский

Citations

1
(NHC)Mn(I) Complex Catalyzed Selective Transfer Hydrogenation of Epoxides, Azoarenes and Nitroarenes Utilizing Ammonia Borane DOI
Saloni Kumari, Souvik Roy,

Kanak Ranjan Saha

et al.

ChemCatChem, Journal Year: 2024, Volume and Issue: 16(21)

Published: July 25, 2024

Abstract Herein, we have reported an effective protocol for the regioselective transfer hydrogenation (TH) of epoxides by utilizing a phosphine‐free bis‐NHC−Mn(I) complex and ammonia borane. By employing this strategy, aromatic were selectively converted to primary alcohols whereas secondary obtained exclusively from aliphatic epoxides. The was further extended TH azoarenes nitroarenes hydrazoarenes anilines respectively. Notably, library substrates with different functional groups screened which resulted in corresponding hydrogenated product good excellent yields. A series mechanistic investigations carried out understand catalytic process.

Language: Английский

Citations

1
A Flexible Synthesis of Polypropionates via Diastereodivergent Reductive Ring‐Opening of Trisubstituted Secondary Glycidols DOI Creative Commons
Katharina Pieper,

Robin Bleith,

Christian Köhler

et al.

Angewandte Chemie International Edition, Journal Year: 2023, Volume and Issue: 63(9)

Published: Dec. 18, 2023

Abstract Polypropionates, characterized by their alternating sequence of stereocenters bearing methyl‐ and hydroxy‐groups, are structurally diverse natural products utmost importance. [1] Herein, we introduce a novel concept approach towards polypropionate synthesis featuring diastereodivergent reductive epoxide‐opening as key step. Readily available stereochemically uniform trisubstituted sec‐glycidols serve branching points for the highly selective all isomers building blocks with three or more consecutive stereocenters. Stereodiversification is accomplished an unprecedented mechanism‐control over complementary modification epoxide's tertiary C‐atom excellent control regio‐ stereoselectivity. Since our method not only suited preparation specific targets but also compound libraries, it will have great impact on synthesis.

Language: Английский

Citations

1
Selective Transformations Mediated by Group 4 Metal Cyclopentadienyl Complexes DOI
J. Pinkas, Martin Lamač

Topics in organometallic chemistry, Journal Year: 2024, Volume and Issue: unknown, P. 117 - 160

Published: Jan. 1, 2024

Language: Английский

Citations

0
Attenuating Nucleophilicity of Titanocene Hydrides beyond Steric Effects en Route to Fatty Alcohols DOI Creative Commons
Andreas Gansäuer, Sebastian Höthker,

Harie Goli

et al.

Chemistry - A European Journal, Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 7, 2024

Here, we introduce a new class of titanocene catalysts for epoxide hydrosilylation that frustrates their hydridicity and thereby emphasizes electron transfer reactivity. This unique attenuation is accomplished by introducing Lewis acidic silicon centers to the cyclopentadienyl ligands an intramolecular coordination titanium-bound hydride. The superiority our rationally designed over classic titanocenes with alkyl-substituted demonstrated in dramatically improved regioselectivity monosubstituted epoxides primary alcohols.

Language: Английский

Citations

0
A Flexible Synthesis of Polypropionates via Diastereodivergent Reductive Ring‐Opening of Trisubstituted Secondary Glycidols DOI Creative Commons
Katharina Pieper,

Robin Bleith,

Christian Köhler

et al.

Angewandte Chemie, Journal Year: 2023, Volume and Issue: 136(9)

Published: Dec. 18, 2023

Abstract Polypropionates, characterized by their alternating sequence of stereocenters bearing methyl‐ and hydroxy‐groups, are structurally diverse natural products utmost importance. [1] Herein, we introduce a novel concept approach towards polypropionate synthesis featuring diastereodivergent reductive epoxide‐opening as key step. Readily available stereochemically uniform trisubstituted sec‐glycidols serve branching points for the highly selective all isomers building blocks with three or more consecutive stereocenters. Stereodiversification is accomplished an unprecedented mechanism‐control over complementary modification epoxide's tertiary C‐atom excellent control regio‐ stereoselectivity. Since our method not only suited preparation specific targets but also compound libraries, it will have great impact on synthesis.

Language: Английский

Citations

0