One-pot sequences of reactions with sol-gel entrapped opposing reagents: an enzyme and metal-complex catalysts

J Am Chem Soc. 2002 Dec 4;124(48):14460-3. doi: 10.1021/ja020799+.

Abstract

We extend our sol-gel methodology of one-pot sequences of reactions with opposing reagents to an enzyme/metal-complex pair. Sol-gel entrapped lipase and sol-gel entrapped RhCl[P(C(6)H(5))(3)](3) or Rh(2)Co(2)(CO)(12) were used for one-pot esterification and C-C double bond hydrogenation reactions, leading to saturated esters in good yields. When only the enzyme is entrapped, the homogeneous catalysts quench its activity and poison it. Thus, when 10-undecenoic acid and 1-pentanol were subjected in one pot to the entrapped lipase and to homogeneously dissolved RhCl[P(C(6)H(5))(3)](3) under hydrogen pressure, only 7% of the saturated 1-pentyl undecanoate was obtained. The yield jumped 6.5-fold when both the enzyme and the catalyst were immobilized separately in silica sol-gel matrixes. Similar one-pot esterifications and hydrogenations by sol-gel entrapped lipase and heterogenized rhodium complexes were carried out successfully with the saturated nonoic, undecanoic, and lauric acids together with several saturated and unsaturated alcohols. The use of (S)-(-)-2-methylbutanol afforded an optically pure ester. The heterogenized lipase is capable of inducing asymmetry during esterification with a prochiral alcohol. Both the entrapped lipase and the immobilized rhodium catalysts can be recovered simply by filtration and recycled in further runs without loss of catalytic activity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alcohols / chemistry
  • Carboxylic Acids / chemistry
  • Catalysis
  • Enzymes, Immobilized / chemistry*
  • Esters / chemical synthesis*
  • Gels / chemistry
  • Lipase / chemistry*
  • Lipase / metabolism
  • Organometallic Compounds / chemistry*
  • Rhodium / chemistry*

Substances

  • Alcohols
  • Carboxylic Acids
  • Enzymes, Immobilized
  • Esters
  • Gels
  • Organometallic Compounds
  • Rhodium
  • Lipase