Katalytische asymmetrische Synthese von Allylalkoholen und Allylalkohol‐Derivaten und deren Anwendung in der organischen Synthese

Abstract

Allylalkohole sind eine wichtige und überaus nützliche Klasse chiraler Bausteine für die organische Synthese. Dieser Aufsatz fasst die Vielzahl an Methoden zur katalytischen asymmetrischen Synthese von enantiomerenangereicherten Allylalkoholen zusammen. Diese umfassen die dynamische kinetische Racematspaltung (DKR/DYKAT), 1,2‐Additionen von Nucleophilen an Carbonylgruppen, allylische Substitutionen, Oxidationen von C‐H‐Bindungen, die Addition von O‐Nucleophilen an π‐Systeme, die Reduktion von ungesättigten Carbonylverbindungen und eine alternative Syntheseroute ausgehend von enantiomerenangereicherten Propargylalkoholen. Darüber hinaus wird der präparative Nutzen dieser katalytischen asymmetrischen Transformationen jeweils am Beispiel ihrer Anwendung in der Synthese komplexer Moleküle wie z. B. Naturstoffen oder potenzieller Therapeutika gezeigt.

Enantioselective Allylic Hydroxylation of ω‐Alkenoic Acids and Esters by P450 BM3 Monooxygenase

“…[1] Extensive research toward the enantioselective synthesis of these moieties has resulted in multistep approaches comprising prefunctionalization and protection group chemistry as well as functional group interconversions and oxidation state manipulations. The direct enantioselective CÀH oxidation of linear terminal olefins offers the shortest route toward these compounds, but known synthetic methods are limited and suffer from low selectivities.…”

Synthesis of Vicinal Aminoalcohols by Stereoselective Aza‐Wacker Cyclizations: Access to (−)‐Acosamine by Redox Relay

“…The aldol reaction is one of many potential routes to enantioenriched allylic alcohols [14] and thus can provide access to enantioenriched aminoalcohol derivatives in connection with our method. An asymmetric aldol reaction enabled the synthesis of the enantioenriched allylic alcohol 9 from crotonaldehyde, [15] which was converted into the corresponding O-allyl hemiaminal 5 p and cyclized cleanly to the oxazolidine 6 p (Scheme 3).…”

Catalytic Asymmetric Arylation of Enals to Enantioenriched Linear Trisubstituted Allylic Secondary Alcohols by using Aryl Lithiums Generated In Situ from Aryl Bromides

“…[2] Dynamic kinetic resolutions [3] and catalytic asymmetric allylic substitutions [4] are the most general among the numerous disclosed methods towards enantioenriched allylic alcohols to date. [5] The acyclic a-substituted terminal diaryl allylic secondary alcohols, one class of trisubstituted allylic alcohols, are rarely disclosed regarding their asymmetric synthesis although a number of allylic secondary alcohols have been prepared through a variety of methods.…”

“…The catalytic asymmetric phenylation of a variety of a-substituted cinnamaldehydes was first investigated and the results included in Table 2. The a-substituted group was vital to high enantioselectivity (entries [1][2][3][4][5][6]. If the a-substituted group R 2 was H, Et, or nPr, the enantioselectivity was lower than 85 %.…”