Title: | 1-alkoxyvinyl esters: renaissance of half-century-old acyl donors with potential applicability |
Address: | "Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871, Japan. kita@phs.osaka-u.ac.jp" |
ISSN/ISBN: | 1527-8999 (Print) 1528-0691 (Linking) |
Abstract: | "Among the various kinds of acyl donors, the 1-alkoxyvinyl esters have characteristic features, such as a high reactivity under nearly neutral conditions and the generation of neutral and volatile esters as single coproducts. Although their use in organic syntheses began in the middle of the 1950s, no significant progress has been seen. This is probably because the existing method of preparing alkoxyvinyl esters used toxic mercuric salts and was not totally applicable for those esters having functionalized acyl moieties. We have discovered that the use of a catalytic amount of the less toxic [RuCl2(p-cymene)]2 effectively accelerates the addition of carboxylic acids to ethoxyacetylene to give ethoxyvinyl esters bearing a variety of functionalized acyl groups in high yields. This discovery has opened a new avenue for developing new reactions and new synthetic methodologies based on the design and use of these acyl donors with suitable functional groups. Such examples include (i) the installation of hydrophilic acyl moieties on biologically active compounds, (ii) asymmetric Pummerer-type reactions, (iii) aromatic Pummerer-type reactions, (iv) the lipase-catalyzed desymmetrization of symmetrical 1,3-diols, and (v) lipase-catalyzed domino reactions. Future possibilities for these acyl donors are also discussed" |
Keywords: | Catalysis Cyclization Esters/*chemical synthesis/chemistry Heterocyclic Compounds/chemical synthesis Kinetics Lipase/chemistry Molecular Conformation Stereoisomerism Vinyl Compounds/*chemical synthesis/chemistry; |
Notes: | "MedlineKita, Yasuyuki Akai, Shuji eng Research Support, Non-U.S. Gov't Review 2005/03/02 Chem Rec. 2004; 4(6):363-72. doi: 10.1002/tcr.20027" |