β-(Carbonatoxy)alkyl radicals: a new subset of β-(ester)alkyl radical fragmentation during copper(I)-mediated synthesis of 1,1-dichloro-1-alkenes
作者:Ram N. Ram、Ram K. Tittal
DOI:10.1016/j.tetlet.2014.05.097
日期:2014.7
A new subset of β-(ester)alkyl radicals is presented. It is the first study on the chemistry of β-(alkoxycarbonyloxy)alkyl radicals that fill the gap in the spectrum of the migrating groups in β-(ester)alkyl radical reactions. The change from less nucleofugal (acetate) group to the more nucleofugal (carbonate) group in the spectrum of the migrating group changed the reaction path from rearrangement
Synthesis of 2,4-disubstituted 3-chlorofurans and the effect of the chlorine substituent in furan Diels–Alder reactions
作者:Ram N. Ram、Neeraj Kumar
DOI:10.1016/j.tetlet.2007.11.193
日期:2008.1
3-chlorofurans were synthesized in 42–69% overall yields by CuCl/bpy-catalyzed halogen atom transfer radical cyclization of 1-substituted 2,2,2-trichloroethyl allyl ethers to 2-substituted 3,3-dichloro-4-(1-chloroalkyl)tetrahydrofurans followed by base promoted dehydrochlorination. Diels–Alderreactions of 4-substituted 2-(2-furyl)-, 2-styryl-, and 2-crotyl-3-chlorofurans with dimethyl acetylenedicarboxylate
Copper(I)/Ligand-Catalyzed 5-<i>endo</i> Radical Cyclization–Aromatization of 2,2,2-Trichloroethyl Vinyl Ethers: Synthesis of 2,3-Difunctionalized 4-Chlorofurans
作者:Ram N. Ram、Dharmendra Kumar Gupta、Vineet Kumar Soni
DOI:10.1021/acs.joc.5b02830
日期:2016.2.19
Copper(I)/ligand-catalyzed one pot synthesis of highly substituted 2,3-difunctionalized-4-chlorofurans has been reported. The reaction proceeds via a Cu(I)-catalyzed regioselective 5-endo-trig radical cyclization of 2,2,2-trichloroethyl vinyl ethers followed by the base-promoted dehydrochlorination. The success of the kinetically disfavored 5-endo cyclization was attributed to the formation of captodatively
Decarboxylative Trichloromethylation of Aromatic Aldehydes and Its Applications in Continuous Flow
作者:Andreas B. Jensen、Anders T. Lindhardt
DOI:10.1021/jo402595r
日期:2014.2.7
Two new protocols for the efficient synthesis of 2,2,2-trichloromethylcarbinols, starting from aromatic aldehydes, have been developed. A combination of sodium trichloroacetate in the presence of malonic acid proved efficient for the transformation of electron deficient aldehydes using DMSO as solvent. Electron-rich aldehydes did, however, not require the addition of malonic acid, affording the desired
An efficient procedure for the deprotection of α,α,α-trihalogen (Cl, Br) methyl alcohols under mild reaction conditions to produce the corresponding aldehydes and haloforms is described. This method can be applied to the deprotection of aromatic, aliphatic, and heterocyclic trihalomethyl alcohol compounds.