Ring-Opening Cyclization of Spirocyclopropanes Using Sulfoxonium Ylides
作者:Yuta Onuki、Hisanori Nambu、Takayuki Yakura
DOI:10.1248/cpb.c20-00132
日期:2020.5.1
cyclohexane-1,3-dione-2-spirocyclopropanes using dimethylsulfoxonium methylide proceeded regioselectively to produce 2,3,4,6,7,8-hexahydro-5H-1-benzopyran-5-ones in good to high yields. The reactions of cycloheptane- and cyclopentane-1,3-dione-2-spirocyclopropanes could construct [7.6]- and [5.6]-fused ring systems. This reaction was also carried out using sulfoxonium ethylide, butylide, and benzylide
A sequential [4 + 2]/[2 + 1] annulation of α-aryl vinylsulfoniums with 2-aminochalcones and 2-(2-aminobenzylidene)-1H-indene-1,3(2H)-dione is reported that affords a series of cyclopropane-fused tetrahydroquinolines. The salient features of this novel and practical transformation include high efficiency, transition-metal-free nature, operational simplicity, and outstanding functional group tolerance
Iodine‐catalyzed ring opening of 1,1‐diacylcyclopropanes for synthesis of fully substituted pyrazole derivatives have been reported. This reaction tolerates a broad range of cyclopropyl ketones and sulfonyl hydrazides to afford useful and densely functionalized pyrazole derivatives with a hydroxy functional group.
Steric bulk controls CO2 absorption: N‐substituted amino acidsalts in poly(ethylene glycol) reversibly absorb CO2 in nearly 1:1 stoichiometry. Carbamic acid is thought to be the absorbed form of CO2; this was supported by NMR and in situ IR spectroscopy, and DFT calculations. The captured CO2 could be converted directly into oxazolidinones and thus CO2 desorption could be sidestepped.
Synthesis of α-Substituted Vinylsulfonium Salts and Their Application as Annulation Reagents in the Formation of Epoxide- and Cyclopropane-Fused Heterocycles
作者:Johnathan V. Matlock、Sven P. Fritz、Stephen A. Harrison、Diane M. Coe、Eoghan M. McGarrigle、Varinder K. Aggarwal
DOI:10.1021/jo501885z
日期:2014.11.7
methods for the synthesis of classes of potentially bioactive molecules remains an important goal for synthetic chemists. Vinylsulfoniumsalts have been used for the synthesis of a wide variety of small heterocyclic motifs; however, further developments to this important class of reagents has been focused on reaction with new substrates rather than development of new vinylsulfoniumsalts. We herein report