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Enantioselective One‐Pot Catalytic Synthesis of 4,5‐Epoxy‐3‐alkanols and 1‐Phenyl‐2,3‐epoxy‐1‐alkanols from α,β‐Unsaturated Aldehydes
Author(s) -
Infante Rebeca,
Hernández Yulan,
Nieto Javier,
Andrés Celia
Publication year - 2013
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201300397
Subject(s) - chemistry , allylic rearrangement , enantioselective synthesis , aldehyde , catalysis , epoxy , stereoselectivity , organic chemistry , reaction conditions , combinatorial chemistry
Conformationally restricted perhydrobenzoxazines have been demonstrated to be good chiral ligands for one‐pot asymmetric ethylation/epoxidation, and the unprecedented arylation/epoxidation of trisubstituted α,β‐unsaturated aldehydes. The scope of the reaction has been studied and a wide set of substrates with allylic strain of different nature has been explored, obtaining good or total diastereoselectivities in all cases. The enantiocontrol was good or high for the ethylation/epoxidation reaction, whereas it remained at moderate or good levels for the arylation/epoxidation. The reaction is general for trisubstituted enals, and alkylic and aromatic substituents are tolerated at both the α‐ and β‐position of the unsaturated aldehyde; however, disubstituted enals remain challenging substrates. When the one‐pot and two‐pot protocols were compared, no significant differences concerning the stereocontrol were found, so the advantages of the one‐pot procedure are clear.