Search results

Search for "lipase" in Full Text gives 61 result(s) in Beilstein Journal of Organic Chemistry.

Coupled chemo(enzymatic) reactions in continuous flow

  • Ruslan Yuryev,
  • Simon Strompen and
  • Andreas Liese

Beilstein J. Org. Chem. 2011, 7, 1449–1467, doi:10.3762/bjoc.7.169

Graphical Abstract
  • ]. From a formal point of view, reactions such as the lipase-catalyzed hydrolysis of triglycerides to glycerol and fatty acids, or amylase-catalyzed hydrolysis of amylose to glucose should also be classified as multistep-reaction processes, because they proceed stepwise via a sequence of intermediates
  • operation to an efficient continuous-flow process (Scheme 7) [28]. The process involves the lipase-catalyzed in situ formation of peracetic acid (20) from hydrogen peroxide and ethyl acetate (19), which oxidizes the model substrate 1-methylcyclohexene (18) to form the product 1-methylcyclohexene oxide (21
  • immobilized Candida antarctica lipase B (Novozym 435) was used as a heterogeneous catalyst in the kinetic resolution of the alcohol 22 [30]. Racemization of the unreacted (S)-22 was achieved with acidic zeolite catalysts. Both heterogenous catalysts were coated with ionic liquids for improved stability of the
PDF
Album
Review
Published 24 Oct 2011

Efficient and selective chemical transformations under flow conditions: The combination of supported catalysts and supercritical fluids

  • M. Isabel Burguete,
  • Eduardo García-Verdugo and
  • Santiago V. Luis

Beilstein J. Org. Chem. 2011, 7, 1347–1359, doi:10.3762/bjoc.7.159

Graphical Abstract
  • . Different examples can be found, in this regard, in the literature. The most common transformations are the kinetic resolution (KR) of secondary alcohols. For example, Matsuda has reported the use of the commercially available supported lipase Novozym 435 for the kinetic resolution of aromatic and
  • Antarctica lipase B (CALB) as the biocatalyst (Scheme 9). In the case of the work by Leitner and Reetz, the CALB enzyme was suspended in a bulk IL phase. At 45 °C and 10.5 MPa and using a substrate:donor ratio of 0.5 they achieved conversions of 43–50% with 99% ee values for the acetate. In a further
  • lipase onto a covalently supported ionic liquid-like phase (SILLP) [105][106]. Those SILLPs are prepared by functionalization of PS–DVB surfaces with IL-like (imidazolium) moieties [107][108]. Experimental results have shown that the resulting surfaces have similar physico-chemical properties to those of
PDF
Album
Review
Published 30 Sep 2011

Achiral bis-imine in combination with CoCl2: A remarkable effect on enantioselectivity of lipase-mediated acetylation of racemic secondary alcohol

  • K. Arunkumar,
  • M. Appi Reddy,
  • T. Sravan Kumar,
  • B. Vijaya Kumar,
  • K. B. Chandrasekhar,
  • P. Rajender Kumar and
  • Manojit Pal

Beilstein J. Org. Chem. 2010, 6, 1174–1179, doi:10.3762/bjoc.6.134

Graphical Abstract
  • Anantapur, Anantapur 515002, Andhra Pradesh, India, Institute of Life Sciences, University of Hyderabad Campus, Gachibowli, Hyderabad 500 046, Andhra Pradesh, India 10.3762/bjoc.6.134 Abstract A bis-imine (prepared via a new FeCl3-based method) in combination with CoCl2 facilitated lipase-mediated
  • acetylation of the (R)-isomer of a racemic benzylic secondary alcohol with 91% ees. The methodology was used for the preparation of the known drug rivastigmine. Keywords: acetylation; bis-imine; cobalt chloride; enantioselectivity; lipase; Introduction The development and use of newer synthetic methods for
  • enantioselectivity was observed in lipase-mediated preparation of alcohols and amines [7][8][9]. These biocatalysts work under mild reaction conditions, and their immobilized forms, being stable in organic solvents, have allowed an easy separation of products and the potential recycling of the enzyme, thereby
PDF
Album
Supp Info
Letter
Published 10 Dec 2010

Miniemulsion polymerization as a versatile tool for the synthesis of functionalized polymers

  • Daniel Crespy and
  • Katharina Landfester

Beilstein J. Org. Chem. 2010, 6, 1132–1148, doi:10.3762/bjoc.6.130

Graphical Abstract
  • in direct miniemulsions with amphiphilic lipases (e.g., lipase-PSTM) [91]. Due to the very large interfacial area available, an apparent molecular weight as large as 200,000 g∙mol−1 could be obtained with full conversion of the monomer after 2 h. Another advantage of miniemulsion systems compared to
PDF
Album
Video
Full Research Paper
Published 01 Dec 2010

Development of dynamic kinetic resolution on large scale for (±)-1-phenylethylamine

  • Lisa K. Thalén and
  • Jan-E. Bäckvall

Beilstein J. Org. Chem. 2010, 6, 823–829, doi:10.3762/bjoc.6.97

Graphical Abstract
  • Lisa K. Thalen Jan-E. Backvall Stockholm University, Department of Organic Chemistry, Arrhenius Laboratory SE-106 91, Stockholm, Sweden 10.3762/bjoc.6.97 Abstract Candida antarctica lipase B (CALB) and racemization catalyst 4 were combined in the dynamic kinetic resolution (DKR) of (±)-1
  • donor. Keywords: dynamic kinetic resolution; kinetic resolution; racemization; Shvo; Candida antartica lipase B; Introduction Chiral amines are important building blocks in the synthesis of many pharmaceuticals, fragrances, and agricultural products, and it is therefore important to develop methods
  • product mixture. However, by racemizing the slower reacting enantiomer in situ, in a process known as dynamic kinetic resolution (DKR) [11], a theoretical yield of 100% can be achieved. We have previously developed a highly efficient protocol for the DKR of primary amines using Candida antarctica lipase B
PDF
Album
Full Research Paper
Published 13 Sep 2010

The development and evaluation of a continuous flow process for the lipase- mediated oxidation of alkenes

  • Charlotte Wiles,
  • Marcus J. Hammond and
  • Paul Watts

Beilstein J. Org. Chem. 2009, 5, No. 27, doi:10.3762/bjoc.5.27

Graphical Abstract
  • lipase B, Novozym® 435, in a preliminary investigation into the development of a continuous flow reactor capable of performing the chemo-enzymatic oxidation of alkenes in high yield and purity, utilising the commercially available oxidant hydrogen peroxide (100 volumes). Initial investigations focussed
  • on the lipase-mediated oxidation of 1-methylcyclohexene, with the optimised reaction conditions subsequently employed for the epoxidation of an array of aromatic and aliphatic alkenes in 97.6 to 99.5% yield and quantitative purity. Keywords: Candida antarctica lipase B; continuous flow; epoxidation
  • ; hydrogen peroxide; lipase; micro reactor; Novozym® 435; peracids; Introduction In addition to their synthetic value as intermediates in the preparation of diols, alcohols, hydroxyesters and alkenes, epoxides are a key raw material in many industrial processes, finding application in adhesives, polymers
PDF
Album
Full Research Paper
Published 02 Jun 2009

Asymmetric reactions in continuous flow

  • Xiao Yin Mak,
  • Paola Laurino and
  • Peter H. Seeberger

Beilstein J. Org. Chem. 2009, 5, No. 19, doi:10.3762/bjoc.5.19

Graphical Abstract
  • have been developed recently, including processes using alternative solvents such as ionic liquids and/or scCO2 [56][57][58][59][60][61]. The kinetic resolution of racemic 1-phenylethanol 54 was performed continuously in scCO2, using an immobilized lipase (Candida antarctica, Novozym 435) and vinyl
  • )- 54 with immobilized lipase in a continuous scCO2- flow reactor. Enantioselective separation of Acetyl-D-Phe in a continuous flow reactor. Acknowledgements We thank the ETH Zürich, Astra Zeneca, and Merck, Sharpe & Dohme for generous financial support of the microreactor program in the Seeberger
PDF
Album
Review
Published 29 Apr 2009

N-acylation of ethanolamine using lipase: a chemoselective catalyst

  • Mazaahir Kidwai,
  • Roona Poddar and
  • Poonam Mothsra

Beilstein J. Org. Chem. 2009, 5, No. 10, doi:10.3762/bjoc.5.10

Graphical Abstract
  • lipase (Novozym® 435) are described and optimum conditions for selective N-acylation rather than O-acylation are also discussed. Microwave assisted solution phase, solid supported and conventional methods were investigated and results were compared. There is a synergy between the enzyme catalysis and
  • microwave irradiation. Keywords: chemoselective; lipase; microwave irradiation; zein number; Introduction Microwave assisted enzyme catalysis is a popular developing methodology in the field of green chemistry [1]. Enzymes have gained pivotal importance in the production of fine chemicals, pharmaceuticals
  • lipase (CAL B Novozym® 435) with fatty acids or esters 1a–h and ethanolamine (2) under simultaneous microwave irradiation. Results and Discussion In the reaction of fatty acids 1a–d or esters of fatty acids 1e–h with ethanolamine (2), two types of acylated products are possible. Out of two possible
PDF
Album
Preliminary Communication
Published 25 Mar 2009

Recent progress on the total synthesis of acetogenins from Annonaceae

  • Nianguang Li,
  • Zhihao Shi,
  • Yuping Tang,
  • Jianwei Chen and
  • Xiang Li

Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48

Graphical Abstract
  • conditions resulted in a smooth conversion of the starting material into THF 89. Triol (+)-90 was obtained with lipase Amano AK desymmetrization. For the appropriate side chain attachment, the termini were differentiated to give lactone (−)-91. Reduction of (−)-91 followed by a Wittig reaction yielded fully
PDF
Album
Review
Published 05 Dec 2008

Diastereoselective and enantioselective reduction of tetralin- 1,4-dione

  • E. Peter Kündig and
  • Alvaro Enriquez-Garcia

Beilstein J. Org. Chem. 2008, 4, No. 37, doi:10.3762/bjoc.4.37

Graphical Abstract
  • precedent for procedures for the asymmetric synthesis of 9. The first involves as the key step kinetic resolution by enzymatic hydrolysis of the corresponding acetate with porcine pancreatic lipase giving (−)-9 in 47% yield and 95% ee [13]. A second approach uses a Pd-catalyzed asymmetric oxidation of meso
PDF
Album
Supp Info
Full Research Paper
Published 22 Oct 2008

Large- scale ruthenium- and enzyme- catalyzed dynamic kinetic resolution of (rac)-1-phenylethanol

  • Krisztián Bogár,
  • Belén Martín-Matute and
  • Jan-E. Bäckvall

Beilstein J. Org. Chem. 2007, 3, No. 50, doi:10.1186/1860-5397-3-50

Graphical Abstract
  • -phenylethanol (2) is addressed. The immobilized lipase Candida antarctica lipase B (CALB) was employed for the resolution, which shows high enantioselectivity in the transesterification. The ruthenium catalyst used, (η 5-C5Ph5)RuCl(CO)2 1, was shown to possess very high reactivity in the "in situ" redox
  • racemization of 1-phenylethanol (2) in the presence of the immobilized enzyme, and could be used in 0.05 mol% with high efficiency. Commercially available isopropenyl acetate was employed as acylating agent in the lipase-catalyzed transesterifications, which makes the purification of the product very easy. In
  • chemistry.[27] In the course of the chemo-enzymatic synthesis of optically pure alcohols and esters, Candida antarctica lipase B (CALB) was found to be one of the most active and selective biocatalysts compared to other enzymes. Lipases do not need the presence of a cofactor and they can be employed in pure
PDF
Album
Supp Info
Full Research Paper
Published 20 Dec 2007
Other Beilstein-Institut Open Science Activities