Synthetic Philosophy: A Study Directed toward Creation of an Ideal Synthetic Method and Its Application for Preventing Global Warming by Combating Desertification

Herein, we report a short and facile stereoselective route to ergoline derivatives. The key steps are a one‐pot Friedel–Crafts alkylation/Michael addition sequence which, in the absence of chiral ligands, affords the trans‐trans‐stereoisomer in 44 % yield as a racemate. Screening of a range of chiral bisoxazoline ligands allowed this sequence to proceed in 42–55 % yields (six examples), with up to 99 % ee. This approach allows for the first time, substitution at the C4‐position and the introduction of 3 chiral centres in one pot. An interesting, base‐mediated conversion of the trans‐trans‐stereoisomer to the cis‐cis‐stereoisomer was discovered and both stereoisomers were characterized by X‐ray crystallography.

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A Tandem Asymmetric Friedel–Crafts Alkylation/Michael Addition: Synthesis of Novel Ergoline Derivatives

Connon

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2019

Eur J Org Chem

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Herein, we report the development of an asymmetric tandem Friedel–Crafts alkylation/Michael addition of 4‐substituted indoles with trans‐β‐nitrostyrene derivatives. By employing a chiral ZnII‐(bis)oxazoline catalyst we could control the formation of three contiguous chiral centers in one step in 57 %–99 % yield and up to > 99 % ee. This methodology provides easy access to a range of novel C4‐substituted products containing the tricyclic core of the ergoline skeleton and allows for the synthesis of tetracyclic ergoline derivatives with four chiral centers, in high enantioselectivity and as single isolated diastereomers.

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Synthetic Philosophy: A Study Directed toward Creation of an Ideal Synthetic Method and Its Application for Preventing Global Warming by Combating Desertification

Cited by 12 publications

References 57 publications

ChemInform Abstract: Synthetic Philosophy: A Study Directed Toward Creation of an Ideal Synthetic Method and Its Application for Preventing Global Warming by Combating Desertification

ChemInform Abstract: Synthetic Philosophy: A Study Directed Toward Creation of an Ideal Synthetic Method and Its Application for Preventing Global Warming by Combating Desertification

Application of a One‐Pot Friedel–Crafts Alkylation/Michael Addition Methodology to the Asymmetric Synthesis of Ergoline Derivatives

A Tandem Asymmetric Friedel–Crafts Alkylation/Michael Addition: Synthesis of Novel Ergoline Derivatives

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