通过迈克尔加成环化反应的α-叠氮基苯并随后进行维蒂希反应,制取2,4,5-三取代的1 H-咪唑和高度取代的吡咯并[1,2- c ]咪唑的新合成策略
摘要:
描述了用于制备高度官能化的1 H-咪唑和5 H-吡咯并[1,2- c ]咪唑的有效而简便的方法。在纯净的条件下加热α-叠氮hal烷和N,N,N',N'-四甲基胍的混合物,通过迈克尔加成环化以相应的产率得到相应的2,4,5-三取代的1 H-咪唑。随后,在二氯甲烷中在三苯膦存在下,将制得的1 H-咪唑与炔属酯进行加成-Wittig反应,以高收率提供5 H-吡咯并[1,2- c ]咪唑。
通过迈克尔加成环化反应的α-叠氮基苯并随后进行维蒂希反应,制取2,4,5-三取代的1 H-咪唑和高度取代的吡咯并[1,2- c ]咪唑的新合成策略
摘要:
描述了用于制备高度官能化的1 H-咪唑和5 H-吡咯并[1,2- c ]咪唑的有效而简便的方法。在纯净的条件下加热α-叠氮hal烷和N,N,N',N'-四甲基胍的混合物,通过迈克尔加成环化以相应的产率得到相应的2,4,5-三取代的1 H-咪唑。随后,在二氯甲烷中在三苯膦存在下,将制得的1 H-咪唑与炔属酯进行加成-Wittig反应,以高收率提供5 H-吡咯并[1,2- c ]咪唑。
A simple protocol to prepare the privileged 2‐aminothiazoles promoted by ferrous sulfate heptahydrate via CN bond formation from vinylazides and commercially available potassium thiocyanate has been developed. A wide range of vinylazides are tolerated to afford the expected polysubstituted 2‐aminothiazoles in reasonably good yields. The use of the non‐toxic substrates and catalyst renders the reaction
A simple and direct synthesis of polysubstituted 4-aminopyrazoles and 4-hydroxypyrazoles from vinyl azides and hydrazines was developed. The present reactions were performed under mild conditions in moderate to excellent yields. A possible mechanism is also proposed.
Facile preparation of 3,5-disubstituted-4-aminothiophene-2-carbaldehyde from a novel unexpected domino reaction of vinyl azides and 1,4-dithiane-2,5-diol
A facile approach to provide 3,5-disubstituted-4-aminothiophene-2-carbaldehyde containing both the amino group and the aldehyde group has been developed.
A novel access to highly functionalized 2-aminonicotinonitriles via efficient annulations of [small alpha]-keto vinyl azides and [small alpha],[small alpha]-dicyanoalkenes is described. This annulation was achieved via base-mediated ring-openings and intramolecular rearrangements. A possible...
A simple and direct synthesis of 2-aminoimidazoles from vinyl azides and cyanamide was developed. An attractive feature of this protocol is that the desired products are generated in a highly efficient and eco-friendly manner without the use of a catalyst. A plausible mechanism has been proposed. (C) 2014 Elsevier Ltd. All rights reserved.