Synthesis of odorants in flow and their applications in perfumery

• Merlin Kleoff,
• Paul Kiler and
• Philipp Heretsch

Beilstein J. Org. Chem. 2022, 18, 754–768, doi:10.3762/bjoc.18.76

• a method for the acetylation of isoamyl alcohol (9) catalyzed by Candida antarctica lipase B (Scheme 3) [26]. A biphasic system consisting of n-heptane and an aqueous buffer solution is used and efficiently mixed in a Corning AFRTM Low Flow reactor providing a fine dispersion of the reaction mixture

Chemical and chemoenzymatic routes to bridged homoarabinofuranosylpyrimidines: Bicyclic AZT analogues

• Sandeep Kumar,
• Jyotirmoy Maity,
• Banty Kumar,
• Sumit Kumar and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2022, 18, 95–101, doi:10.3762/bjoc.18.10

• % overall yield starting from compound 11, respectively (Scheme 2). The use of lipase as biocatalyst was employed for the selective acetylation of the primary hydroxy group present in trihydroxy nucleosides 14a,b. This led to the screening of two different lipases, viz Candida antarctica lipase-B (CAL-B

Synthetic strategies toward 1,3-oxathiolane nucleoside analogues

• Umesh P. Aher,
• Dhananjai Srivastava,
• Girij P. Singh and
• Jayashree B. S

Beilstein J. Org. Chem. 2021, 17, 2680–2715, doi:10.3762/bjoc.17.182

• -friendliness. Ren and colleagues [59] recently reported the preparation of an enantiopure 1,3-oxathiolane 65 utilizing a multienzymatic cascade protocol (Scheme 21). The combined use of surfactant-treated Subtilisin Carlsberg (STS) and Candida antarctica lipase B (CAL-B) resulted in the 1,3-oxathiolane ring in

Coupling biocatalysis with high-energy flow reactions for the synthesis of carbamates and β-amino acid derivatives

• Alexander Leslie,
• Thomas S. Moody,
• Megan Smyth,
• Scott Wharry and
• Marcus Baumann

Beilstein J. Org. Chem. 2021, 17, 379–384, doi:10.3762/bjoc.17.33

• within continuous flow processes [17][18][19][20] to provide a greener and more chemoselective means for the synthesis of drug-like targets. Recently, we reported on an innovative telescoped process using immobilized CALB (Candida antarctica lipase B) to enable the conversion of residual benzyl alcohol

Thiol-free chemoenzymatic synthesis of β-ketosulfides

• Adrián A. Heredia,
• Martín G. López-Vidal,
• Marcela Kurina-Sanz,
• Fabricio R. Bisogno and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2019, 15, 378–387, doi:10.3762/bjoc.15.34

• activity (89–99% conversion) was found for Candida antarctica lipase B (CAL-B, Novozym® 435) in all tested conditions (Table 1, entry 2). For porcine pancreas lipase (PPL), a different scenario was found, since conversion was strongly influenced by buffer composition and, to a lesser extent, the cosolvent

• % ketosulfoxide 3; 70% ketosulfone 4, Scheme 4). Conclusion In this work we have shown the development of a versatile chemoenzymatic methodology for the efficient preparation of β-ketosulfides avoiding the use of thiols. Candida antarctica lipase B resulted active in the presence of any tested cosolvent

Nanoreactors for green catalysis

• M. Teresa De Martino,
• Loai K. E. A. Abdelmohsen,
• Floris P. J. T. Rutjes and
• Jan C. M. van Hest

Beilstein J. Org. Chem. 2018, 14, 716–733, doi:10.3762/bjoc.14.61

• stabilized by colloidal particles that adsorb at the water–oil interface. They are more stable than classical emulsions and do not require the usage of small molecule surfactants. This is a big advantage in downstream processing and product and catalyst recovery. The enzyme Candida antarctica lipase B (CalB

Position-dependent impact of hexafluoroleucine and trifluoroisoleucine on protease digestion

• Susanne Huhmann,
• Anne-Katrin Stegemann,
• Kristin Folmert,
• Damian Klemczak,
• Johann Moschner,
• Michelle Kube and
• Beate Koksch

Beilstein J. Org. Chem. 2017, 13, 2869–2882, doi:10.3762/bjoc.13.279

• assay [30]. Substitution of tryptophan, tyrosine, and phenylalanine residues in a glycosylation-deficient mutant of Candida antarctica lipase B, CalB N74D, by their monofluorinated analogues, left the resistance to proteolytic degradation by proteinase K unchanged [31]. Incorporation of α-fluoroalkyl

Correction: Mechanochemical enzymatic resolution of N-benzylated-β³-amino esters

• Mario Pérez-Venegas,
• Gloria Reyes-Rangel,
• Adrián Neri,
• Jaime Escalante and
• Eusebio Juaristi

Beilstein J. Org. Chem. 2017, 13, 2128–2130, doi:10.3762/bjoc.13.210

• . Universidad 1001, Cuernavaca, Morelos, 62210, Mexico El Colegio Nacional, Luis Gonzáles Obregón 23, Centro Histórico, Ciudad de México, 06020, Mexico 10.3762/bjoc.13.210 Keywords: ball-milling; β3-amino acid; Candida antarctica lipase B; enzymatic resolution; mechanochemistry; The original published Tables

Enzymatic separation of epimeric 4-C-hydroxymethylated furanosugars: Synthesis of bicyclic nucleosides

• Neha Rana,
• Manish Kumar,
• Vinod Khatri,
• Jyotirmoy Maity and
• Ashok K. Prasad

Beilstein J. Org. Chem. 2017, 13, 2078–2086, doi:10.3762/bjoc.13.205

• different lipases, i.e., Thermomyces lanuginosus lipase immobilized on silica (Lipozyme® TL IM) and Candida antarctica lipase-B immobilized on polyacrylate (Lewatit), commonly known as Novozyme®-435 in five different organic solvents, viz. 2-methyltetrahydofuran (2-methyl-THF), acetonitrile (MeCN

• of synthetic carbohydrate and nucleoside chemistry. Experimental The Candida antarctica lipase-B (CAL-B or Novozyme®-435) immobilized on polyacrylate was purchased from Sigma-Aldrich Co. (USA). Theremomyces lanuginosus lipase (Lipozyme TL IM) immobilized on silica was obtained as a gift from

Mechanochemical enzymatic resolution of N-benzylated-β³-amino esters

• Mario Pérez-Venegas,
• Gloria Reyes-Rangel,
• Adrián Neri,
• Jaime Escalante and
• Eusebio Juaristi

Beilstein J. Org. Chem. 2017, 13, 1728–1734, doi:10.3762/bjoc.13.167

• resolution of racemic β3-amino esters employing Candida antarctica lipase B (CALB) to afford highly valuable enantioenriched N-benzylated-β3-amino acids in good yields. Furthermore the present protocol is readily scalable. Keywords: ball-milling; β3-amino acid; Candida antarctica lipase B; enzymatic

• ][18][19][20][21][22] including strategies based on organocatalysis [23][24][25][26] and kinetic resolution using enzymes such as Candida antarctica lipase B, which was shown to be efficient in the resolution of racemic β-amino acids under various conditions [27][28][29][30]. Among recent developments

• applications on a large scale [45][46]. Very recently, Hernández, Frings, and Bolm developed a method to carry out the kinetic resolution of secondary alcohols through selective acylation using Candida antarctica lipase B, under solvent-free ball-milling conditions [47][48]. Inspired by this ground-breaking

Dicarboxylic esters: Useful tools for the biocatalyzed synthesis of hybrid compounds and polymers

• Ivan Bassanini,
• Karl Hult and
• Sergio Riva

Beilstein J. Org. Chem. 2015, 11, 1583–1595, doi:10.3762/bjoc.11.174

• in the esterification of the antineoplastic antibiotics mithramycin (5) catalyzed by Candida antarctica lipase A (CAL-A) and chromomycin A3 (6) catalyzed by Candida antarctica lipase B (CAL-B) [24]. In another report a series of mono-substituted troxerutin esters (7a) were synthesized by action of

First chemoenzymatic stereodivergent synthesis of both enantiomers of promethazine and ethopropazine

• Paweł Borowiecki,
• Daniel Paprocki and
• Maciej Dranka

Beilstein J. Org. Chem. 2014, 10, 3038–3055, doi:10.3762/bjoc.10.322

• that generated ester (R)-(−)-6a was enantiomerically pure (>99% ee) regardless of the time and the conversion. In turn, the reaction rate was considerably improved in Novozym 435-catalyzed analytical scale acetylation. This revealed that Candida antarctica lipase B (CAL-B) immobilized on acrylic resin

cis–trans Isomerization of silybins A and B

• Michaela Novotná,
• Radek Gažák,
• David Biedermann,
• Florent Di Meo,
• Petr Marhol,
• Marek Kuzma,
• Lucie Bednárová,
• Kateřina Fuksová,
• Patrick Trouillas and
• Vladimír Křen

Beilstein J. Org. Chem. 2014, 10, 1047–1063, doi:10.3762/bjoc.10.105

• diastereoisomers were separated by lipase-catalyzed discrimination [5]. Candida antarctica lipase B (Novozym 435) was from Novozymes (DK). All other reagents were of analytical grade and used without further purification. (2R,3S,10R,11R)-23-O-Acetylsilybin (12): BF3·OEt2 (2 mL, 15.926 mmol, 50% solution in OEt2

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

• 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

• )-24 at 98% conversion and a space-time yield of 50 g L−1 day−1. Operational stability was maintained over a period of 14 days. Previously applied Candida antarctica lipase B immobilized on modified C4-silica proved to be unstable upon combination with acidic chemocatalysts. Separation of the acidic

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

• 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

• flow biocatalytic systems in which the IL phase acts as the stationary phase and the scF becomes the mobile phase [98]. Pioneering work in this field was carried out by the groups of Lozano and Leitner and Reetz [99][100]. Both groups studied the kinetic resolution of phenylethanol with Candida

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

• enhancing their economic viability [10][11]. Recently, we have observed that achiral bis-imines in combination with CoCl2 improved the enantioselectivity substantially in CAL-B (Candida antarctica lipase B) [12][13] mediated acetylation of a racemic secondary alcohol with vinyl acetate. Here we report our

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

• 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

• 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

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

• 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

• alkene epoxidation via the chemo-enzymatic perhydrolysis of ethyl acetate using Novozym® 435 (4), immobilised Candida antarctica lipase B, and UHP (3). They utilised the high specificity of Candida antarctica lipase B towards ester hydrolysis to generate acetic acid (1) in situ and subsequently

• alternative to traditional techniques. With this in mind, we report herein the development and evaluation of continuous flow technique for the enzyme-mediated synthesis of epoxides, employing the immobilised Candida antarctica lipase B, Novozym® 435 (4). This was recently found to be the most efficient

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

• . The quantities of reactant and enzyme for reaction procedure were identical to those used for conventional heating. Lipase A lipase from Candida antarctica (Lipase B, a non specific lipase) immobilized on macroporous acrylic resin designated “Novozym® 435”, was a gift from Novozymes, Denmark. HPLC The

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

• -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

• 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

• , Candida antarctica lipase B, catalyzes the transesterification with excellent selectivity in the presence of the homogeneous ruthenium racemization catalyst 1. Isopropenyl acetate seems to be an appropriate acyl donor, which makes the purification of the product acetate very easy via simple distillation