diazomethylphosphonate leading to the formation of two different types of products is reported. The reaction carried out in acetone in the presence of catalytic amount of cesium fluoride afforded spiropyrazoline phosphonates via 1,3-dipolar cycloaddition reaction, whereas the reaction in methanol yielded an interesting class of pyrazolylphthalides. This strategy provides an efficient alternative method
Palladium‐Catalyzed Asymmetric [4+2] Cycloaddition of 2‐Methylidenetrimethylene Carbonate with Alkenes: Access to Chiral Tetrahydropyran‐Fused Spirocyclic Scaffolds
A palladium‐catalyzed asymmetric [4+2] cycloaddition of 2‐methylidenetrimethylene carbonate with alkenes derived from pyrazolones, indandione, or barbiturate has been successfully developed, affording pharmacologically interesting chiral tetrahydropyran‐fused spirocyclic scaffolds. The target compounds were generated in good to excellent yields and with high enantioselectivity (up to 99 % ee ). Furthermore
Multicomponent All-Carbon Cascade and Sequential Annulation: Construction of Functionalized Decalins
作者:Yuan Zhong、Guichen Li、Dan Zhang、Long Hao、Zhengjun Cai
DOI:10.1021/acs.orglett.3c01379
日期:2023.6.9
decalin derivatives. The reaction strategy consisted of a consecutive Michael/Michael/tautomerization/Michael/Aldol annulation sequence and involved organic amine catalysts, mild conditions, and high stereoselectivity. This strategy, using a one-pot approach, resulted in the construction of four C–C bonds and the formation of fused carbocyclic decalin derivatives.
Palladium‐Catalyzed [4+2] Cycloaddition of Vinyl Benzoxazinanones with 1,3‐Indanedione: Approach to Spiro‐Tetrahydroquinoline Scaffolds
作者:Qinglang Wei、Liang Tu、Sen Li、Yongsheng Zheng、Jikai Liu
DOI:10.1002/ejoc.202300499
日期:2023.10.16
A palladium catalyzed decarboxylative [4+2] cycloaddition of vinyl benzoxazinanones with 1,3-indanedione was developed, affording a series of biologically potential spiro-tetrahydroquinolines. Gram-scale synthesis and product elaboration demonstrated the utility of this method. The product demonstrated exhibited potency in inhibiting MDA-MB-231 cell line.
[Display omitted] An interesting product divergence in the reaction of trifluorodiazoethane with arylidene-1,3-indanediones is reported. The reaction conducted using 10 mol% of silver carbonate afforded trifluoromethylspiropyrazolines, while with excess of cesium fluoride in methanol, the cycloaddition was followed by nucleophilic ringopening of the spiropyrazoline to afford trifluoromethylated -ca