Crampton R.H.,University of Nottingham |
Fox M.,Dr. Reddys Laboratories EU Ltd |
Woodward S.,University of Nottingham
Tetrahedron Asymmetry | Year: 2013
The sequential reaction of chlorosulfonyl isocyanate with t-BuOH, t-BuNH2 and TFA allows formation of H2NSO 2NHBut. Condensation of the latter with Ar1CHO in the presence of Ti(OEt)4 provides the activated imines Ar 1CHNSO2NHBut (59-89%). Commercially available boronic acids add to these imines with good stereoselectivity (76-98% ee) using readily available diene ligands. Simple deprotection with 5% w/w water in pyridine affords free Ar1CHNH2Ar2. © 2013 Elsevier Ltd. All rights reserved.
DR. REDDYS LABORATORIES EU Ltd | Date: 2011-10-25
University of Edinburgh and DR. REDDYS LABORATORIES EU Ltd | Date: 2012-04-10
Cobley C.J.,Chirotech Technology Ltd |
Hanson C.H.,Dr. Reddys Laboratories EU Ltd |
Lloyd M.C.,Chirotech Technology Ltd |
Simmonds S.,Chirotech Technology Ltd |
Peng W.J.,Nantong Cellulose Fibers Co.LTD
Organic Process Research and Development | Year: 2011
The compound, (S)-2-amino-5-[1,3]dioxolan-2-yl-pentanoic acid [(S)-allysine ethylene acetal], is a key intermediate in a number of angiotension-I converting enzyme (ACE) and neutral endopeptidase (NEP) inhibitors currently in clinical trials. Through a combination of our hydroformylation and biocatalysis technologies we have developed an efficient five-step synthetic route to this material starting from crotonaldehyde. The development of this process, leading to a large-scale commercial manufacturing campaign, is described in this paper. © 2010 American Chemical Society.
Tomaszewski B.,TU Dortmund |
Lloyd R.C.,Dr. Reddys Laboratories EU Ltd |
Warr A.J.,Dr. Reddys Laboratories EU Ltd |
Buehler K.,TU Dortmund |
Schmid A.,TU Dortmund
ChemCatChem | Year: 2014
Microreactors provide higher mass transfer rates than do conventional batch reactors. A tube-in-tube microreactor was used for the NADH-dependent in vitro conversion of 2-hydroxybiphenyl to 3-phenylcatechol that was catalysed by 2-hydroxybiphenyl 3-monooxygenase. A biphasic reaction system allowed high substrate loadings, whereas the microreactor ensured excellent mass transfer rates between the organic and aqueous phases. Oxygen was supplied continuously by membrane aeration across the whole reaction compartment. The productivities achieved in the tube-in-tube microreactor were 38 times higher than those in previously described batch reactors and almost 4 times higher than for the same reaction in a microreactor in which aqueous, organic, and air phases were delivered through consecutive segments. This set-up is a promising concept for oxygen-dependent biocatalytic reactions in microreactors and is developing as a basis for applications in gram-scale organic biosyntheses. Flow power: A tube-in-tube reactor is presented for a gas-dependent biocatalytic reaction, overcoming typical limitations such as mass transfer, product and substrate inhibition, and challenges with gas delivery with productivities superior to standard batch reactors or conventional microreactors. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.