A fast and highly enantioselectivefluorination of [small beta]-keto esters catalyzed by diphenylamine linked bis(oxazoline)-Cu(OTf)2 complexes under solvent-free conditions has been developed using a planetary ball mill.
Enantioselective Fluorination Mediated by Cinchona Alkaloid Derivatives/Selectfluor Combinations: Reaction Scope and Structural Information for <i>N</i>-Fluorocinchona Alkaloids
Cinchona-alkaloid/Selectfluor combinations efficiently fluorinate a variety of carbonyl compounds in a highly enantioselective manner to furnish chiral alpha-fluorocarbonyl compounds. The DHQB/Selectfluor combination is effective for the enantioselective fluorination of indanones and tetralones 1 in up to 91% ee. The first enantioselective syntheses of chiral derivatizing reagents 3 was accomplished with high ee and in
several limitations in both chemical yields and enantioselectivities of the fluorinated products. We present here the background of our personal story of the enantioselectivefluorination reaction and some successful applications of the methods to the design and synthesis of biologically active products. Two novel approaches using cinchonaalkaloid/Selectfluor® combinations and chiral ligands/metal complexes
Iron(iii)–salan complexes catalysed highly enantioselective fluorination and hydroxylation of β-keto esters and N-Boc oxindoles
作者:Xin Gu、Yan Zhang、Zhen-Jiang Xu、Chi-Ming Che
DOI:10.1039/c4cc01631a
日期:——
Chiral iron(III)âsalan complexes catalysed highly enantioselective α-fluorination and α-hydroxylation of β-keto esters and N-Boc oxindoles to give the corresponding products in high yields and good-to-excellent ee values under mild reaction conditions.
Enantioselective Fluorination of β-Ketoesters Catalyzed by Chiral Sodium Phosphate: Remarkable Enhancement of Reactivity by Simultaneous Utilization of Metal Enolate and Metal Phosphate
作者:Keiji Mori、Ayaka Miyake、Takahiko Akiyama
DOI:10.1246/cl.130934
日期:2014.1.5
A highly enantioselective fluorination of β-ketoesters catalyzed by chiral sodium phosphate is achieved. In this process, the simultaneous formation of sodium enolate and sodium phosphate under basic conditions is the key to achieving excellent selectivity. Indanone derivatives as well as benzofuranone derivatives could be employed in this reaction to afford the fluorinated adducts in good yields with good to excellent enantioselectivities.