Substrate-controlled Michael additions of chiral ketones to enones

Substrate-controlled Michael additions of the titanium-(IV) enolate of lactate-derived ketone 1 to acyclic α,β-unsaturated ketones in the presence of a Lewis acid (TiCl4 or SnCl4) provide the corresponding 2,4-anti-4,5-anti dicarbonyl compounds in good yields and excellent diastereomeric ratios. Lik...

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Bibliographic Details
Authors: Fàbregas, Mireia; Gómez Palomino, Alejandro; Pellicena Zanón, Miquel; Reina, D.F.; Romea, Pedro; Urpí Tubella, Fèlix; Font Bardia, Ma. Mercedes
Format: Article
Status:Accepted version
Publication date:2014
Country:España
Institution:Universidad de Barcelona
Repository:Dipòsit Digital de la UB
OAI Identifier:oai:diposit.ub.edu:2445/169228
Online Access:https://hdl.handle.net/2445/169228
Access Level:Open access
Keyword:Àcids de Lewis
Titani
Cetones
Lewis acids
Titanium
Ketones
Description
Summary:Substrate-controlled Michael additions of the titanium-(IV) enolate of lactate-derived ketone 1 to acyclic α,β-unsaturated ketones in the presence of a Lewis acid (TiCl4 or SnCl4) provide the corresponding 2,4-anti-4,5-anti dicarbonyl compounds in good yields and excellent diastereomeric ratios. Likely, the nucleophilic species involved in such additions are bimetallic enolates that may add to enones through cyclic transition states. Finally, further studies indicate that a structurally related β-benzyloxy chiral ketone can also participate in such stereocontrolled conjugate additions.