Prieto E, Infante R, Nieto J, Andrés C. Dimethylzinc-mediated enantioselective addition of terminal alkynes to 1,2-diketones using perhydro-1,3-benzoxazines as ligands.
Org Biomol Chem 2021;
19:3859-3867. [PMID:
33949556 DOI:
10.1039/d1ob00249j]
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Abstract
A conformationally restricted perhydro-1,3-benzoxazine derived from (-)-8-aminomenthol behaves as a good chiral ligand in the dimethylzinc-mediated enantioselective monoaddition of aromatic and aliphatic terminal alkynes to 1,2-diketones. The corresponding α-hydroxyketones were obtained in good yields with high enantioselectivities starting from both aromatic and aliphatic 1,2-diketones. The alkynylation of unsymmetrical 1,2-diketones with electronically different substituents also proceeds with high regio- and enantioselectivity. This reaction provides a practical method to synthesize ketones bearing a chiral tertiary propargylic alcohol.
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