Asymmetric reduction of ketones using recombinant E. coli cells that produce a versatile carbonyl reductase with high enantioselectivity and broad substrate specificity
The gene encoding a versatile biocatalyst that shows highenantioselectivity for a variety of ketones, SCR (Saccharomyces cerevisiae carbonyl reductase), has been identified, cloned, and expressed in Escherichia coli. Two types of expression systems with high NADPH-regenerating capacities have been constructed. One is the tandem system, where the genes encoding SCR and GDH (glucose dehydrogenase) are
编码,显示出对多种酮具有高对映选择性的通用基因的基因SCR(酿酒酵母羰基还原酶)已在大肠杆菌中鉴定,克隆和表达。已经构建了具有高NADPH再生能力的两种类型的表达系统。一个是串联系统,其中编码SCR和GDH(葡萄糖脱氢酶)的基因位于同一质粒中,另一个是双质粒系统,其中SCR和GDH的每个基因位于可以共存的单独质粒中在一个大肠杆菌细胞中 重组大肠杆菌不对称还原酮细胞产生合成有用的20种醇,其中11种对映体纯。这些产品之一的生产率高达41 g / L。
Efficient synthesis of β-amino-α,β-unsaturated carbonyl compounds
β-enaminones is presented: in the presence of tetraethyl orthosilicate, a number of highly functional β-enamino esters were obtained; this method provided an alternative for the formation of β-amino-α,β-unsaturated carbonyl compounds with mild and functional group compatible reaction conditions.
Synthesis of 1,4-Diazepanes and Benzo[<i>b</i>][1,4]diazepines by a Domino Process Involving the <i>In Situ</i> Generation of an Aza-Nazarov Reagent
作者:Swarupananda Maiti、Marco Leonardi、Ángel Cores、Giammarco Tenti、M. Teresa Ramos、Mercedes Villacampa、J. Carlos Menéndez
DOI:10.1021/acs.joc.0c01774
日期:2020.9.18
A step- and atom-economical protocol allowing the synthesis of 1,4-diazepanes and also tetrahydro- and decahydro-1,5-benzodiazepines is described. The method proceeds from very simple starting materials such as 1,2-diamines and alkyl 3-oxohex-5-enoates and can be performed under solvent-free conditions in many instances. The key event of this process was the generation in situ of an aza-Nazarov reagent
描述了一种步骤和原子经济的方案,其允许合成1,4-二氮杂庚烷以及四氢-和十氢-1,5-苯并二氮杂pine。该方法从非常简单的起始原料,例如1,2-二胺和3-氧杂己基-5-烯酸烷基酯出发,在许多情况下可以在无溶剂条件下进行。该过程的关键事件是aza-Nazarov试剂的原位生成及其随后的分子内aza-Michael环化。还建立了反应的分子间形式,并将其用于吡咯并[1,2- a ] [1,5]重氮骨架的第一个实例的合成。
First Synthesis of α,β-Unsaturated Lactones with High Diversity through the Passerini Reaction and Ring-Closing Metathesis (RCM)
作者:Almuth Schwäblein、Jürgen Martens
DOI:10.1002/ejoc.201100160
日期:2011.8
A new class of α,β-unsaturated pyran-2-carboxamides was easily accessed by a multicomponent reaction (MCR), followed by a ring-closingmetathesis (RCM) using a ruthenium catalyst. In the first step, α-acyloxy carboxamides with two terminal double bonds were formed from terminal unsaturated carboxylic acids, allyl ketones, and isocyanides (Passerinireaction, P-3CR).