Solvent-free condensations of ketones with malononitrile catalysed by methanesulfonic acid/morpholine system
作者:M. Góra、B. Kozik、K. Jamroży、M. K. Łuczyński、P. Brzuzan、M. Woźny
DOI:10.1039/b820901d
日期:——
The preparation of ylidenemalononitriles viaKnoevenagel condensations of ketones with malononitrile under solvent-free conditions is described. Good yields and short reaction time are the features observed with methanesulfonic acid (MSA)/morpholine used as the catalyst. The wide applicability of the protocol is shown by the fact that not only unconjugated, but also aryl-alkyl ketones gave satisfactory
Copper-Catalyzed Enantioselective Arylation via Radical-Mediated C–C Bond Cleavage: Synthesis of Chiral ω,ω-Diaryl Alkyl Nitriles
作者:Guo-Qing Cui、Jing-Cheng Dai、Yan Li、Yuan-Bo Li、Duo-Duo Hu、Kang-Jie Bian、Jie Sheng、Xi-Sheng Wang
DOI:10.1021/acs.orglett.1c02725
日期:2021.10.1
The first example of copper-catalyzed ring-opening, enantioselective arylation of cyclic ketoxime esters to access ω,ω-diaryl alkyl nitriles has been developed in high yield (up to 92% yield) with excellent enantioselectivity (up to 91% ee). Side-arm bis(oxazoline) ligand plays a significant role in this asymmetric catalytic transformation, which provides an efficient route to construct diverse chiral
Highly Efficient and Enantioselective α-Arylation of Cycloalkanones by Scandium-Catalyzed Diazoalkane-Carbonyl Homologation
作者:Jason Kingsbury、Victor Rendina、Hilan Kaplan
DOI:10.1055/s-0031-1289650
日期:2012.3
Functionalized α-tertiary and -quaternary 2-arylcycloalkanones are rapidly accessed by scandium(III) triflate-catalyzed diazoalkane-carbonyl homologations. Recent developments have allowed for carbon insertion reactions to be performed with catalyst loadings as low as 0.5 mol% on scales up to 5 mmol. Pairing readily available bis- and tris(oxazoline) based ligands with scandium triflate allows access to arylated medium ring carbocycles with enantioselectivities up to 98:2 er and >98% yield. The formal C-C insertion of aryldiazomethanes into unsubstituted cycloalkanones provides a single-step solution to the ongoing challenge of α-arylation.
Naphthopyrans annelated in C5-C6, their preparation and compositions and (CO)polymer matrices containing them
申请人:——
公开号:US20020197562A1
公开(公告)日:2002-12-26
The present invention relates to novel compounds of the naphthopyran type which have an annelated carbocycle in position 5,6. These compounds are of formula (I) given below:
1
in which A is an alicyclic ring which is optionally annelated with an aromatic ring and in which two adjacent R
3
can together form at least one ring, for example a benzo group. These compounds (I) possess interesting photochromic properties. The invention also relates to the method of preparing these compounds (I), as well as their applications as photochromes and compositions and (co)polymer matrices comprising them.