Wolfgang Kroutil

Bio: Wolfgang Kroutil is an academic researcher from University of Graz. The author has contributed to research in topics: Biocatalysis & Enantioselective synthesis. The author has an hindex of 60, co-authored 367 publications receiving 12261 citations. Previous affiliations of Wolfgang Kroutil include University of Liverpool & Technische Universität München.

Artificial Biocatalytic Linear Cascades for Preparation of Organic Molecules

Abstract: The review compiles artificial cascades involving enzymes with a focus on the last 10 years. A cascade is defined as the combination of at least two reaction steps in a single reaction vessel without isolation of the intermediates, whereby at least one step is catalyzed by an enzyme. Additionally, cascades performed in vivo and in vitro are discussed separately, whereby in vivo cascades are defined here as cascades relying on cofactor recycling by the metabolism or on a metabolite from the living organism. The review introduces a systematic classification of the cascades according to the number of enzymes in the linear sequence and differentiates between cascades involving exclusively enzymes and combinations of enzymes with non-natural catalysts or chemical steps. Since the number of examples involving two enzymes is predominant, the two enzyme cascades are further subdivided according to the number, order, and type of redox steps. Furthermore, this classification differentiates between cascades where al...

Recent Developments of Cascade Reactions Involving ω‑Transaminases

Abstract: Enzymatic cascade reactions experience tremendous attention by cutting short conventional step-by-step synthesis in a highly efficient and elegant fashion. Focusing on ω-transaminases, this review provides an overview of different biocatalytic strategies to afford a variety of (chiral) amines employing diverse cascade systems: Cascades to shift the reaction equilibrium as well as cascades for the amination of alcohols and nonactivated C–H bonds are discussed. Cascades enable the deracemization of rac-amines, other ones involve biocatalyzed C–C bond formation and C–C bond hydrolysis. Finally, the potential of spontaneous ring closure reactions initiated by ω-transaminases is illustrated.

Formal Asymmetric Biocatalytic Reductive Amination

Abstract: Asymmetric methods to prepare optically active a-chiral primary amines are highly demanded in asymmetric synthesis owing to the biological/pharmacological activity of many amines. Various techniques have been reported, such as asymmetric 1,2-addition to imines and asymmetric amination of a,a-disubstituted aldehydes, transformation of allylic alcohols into amines, (dynamic) kinetic resolution, and cyclic deracemization employing racemic amines as substrates. Asymmetric reductive amination of ketones has been investigated with transition-metal catalysts and organocatalysts, as well as via sulfinyl imine intermediates. Although tremendous progress in organo/metal catalysis has been achieved for the asymmetric reductive amination of ketones to access a-chiral amines, improved protocols are still required that are simple, green, and economically viable and that lead to high enantiomeric excesses. Biocatalytic reductive amination or transamination is well established for accessing a-amino acids from the corresponding a-keto carboxylic acids. However, the situation is different for primary amines that are not adjacent to a carbonic acid moiety. w-Transaminases have recently received attention for the preparation of such a-chiral unprotected amines. w-Transaminases are employed mainly in one way, namely for the kinetic resolution of racemic chiral amines; only a few reports deal with asymmetric synthesis by starting from a prochiral ketone, probably due to problems in shifting the equilibrium to the product side, as well as due to the moderate stereoselectivity of the employed w-transaminases. These asymmetric synthetic processes usually require at least stoichiometric amounts of an amine donor (for example, alanine). The latter leads to a side product (pyruvate), which has to be removed during the transformation by using, for instance, pyruvate decarboxylase or lactate dehydrogenase. Additionally, limitations due to inhibition by the product amine and by pyruvate have been reported. An ideal process would use ammonium as the amine donor, together with a cheap reducing agent (for example, formate, hydrogen, or glucose; see Scheme 1). Even

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

Enzyme immobilization: The quest for optimum performance

Abstract: Immobilization is often the key to optimizing the operational performance of an enzyme in industrial processes, particularly for use in non-aqueous media. Different methods for the immobilization of enzymes are critically reviewed. The methods are divided into three main categories, viz. (i) binding to a prefabricated support (carrier), (ii) entrapment in organic or inorganic polymer matrices, and (iii) cross-linking of enzyme molecules. Emphasis is placed on relatively recent developments, such as the use of novel supports, e.g., mesoporous silicas, hydrogels, and smart polymers, novel entrapment methods and cross-linked enzyme aggregates (CLEAs).

Cascade reactions in total synthesis.

Abstract: The design and implementation of cascade reactions is a challenging facet of organic chemistry, yet one that can impart striking novelty, elegance, and efficiency to synthetic strategies. The application of cascade reactions to natural products synthesis represents a particularly demanding task, but the results can be both stunning and instructive. This Review highlights selected examples of cascade reactions in total synthesis, with particular emphasis on recent applications therein. The examples discussed herein illustrate the power of these processes in the construction of complex molecules and underscore their future potential in chemical synthesis.