From one to two quaternary centers : ester or nitrile α-alkylation applied to bioactive alkaloids
Abstract
The synthesis of all-carbon quaternary centers remains a challenge. Here we describe studies on the formation of two adjacent all-carbon quaternary centers in the context of the planned synthesis of the bioactive natural products perophoramidine and the communesins. In one approach the key step involves ester-alkylation using either allyl bromide or formaldehyde as the electrophile. An unexpected rapid auto-oxidation reaction during the synthesis of the alkylation substrates limited the scalability of this approach. In a second route, alkylation of a nitrile-containing precursor was planned. The use of the TosMIC reagent on a complex substrate gave the nitrile for alkylation. The assignment of the relative stereochemistry of the products was done through the extensive use of small molecule X-ray crystallography.
Citation
Voûte , N , Neal , A , Medda , F , Johnston , C A , Slawin , A M Z & Westwood , N J 2018 , ' From one to two quaternary centers : ester or nitrile α-alkylation applied to bioactive alkaloids ' , Tetrahedron , vol. In press . https://doi.org/10.1016/j.tet.2018.10.077
Publication
Tetrahedron
Status
Peer reviewed
ISSN
0040-4020Type
Journal article
Rights
Copyright © 2018 Elsevier Ltd. This work has been made available online in accordance with the publisher’s policies. This is the author created, accepted version manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1016/j.tet.2018.10.077
Description
The authors would like to acknowledge EPSRC for PhD funding through the Doctoral Training Schemes.Collections
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