Synthesis, Structure, and Reactions of NH-Bridged Calix[m]arene[n]pyridines
摘要:
NH-bridged calix[1]arene[3]pyridine and calix[2]arene[2]pyridine were synthesized readily from efficient deprotection of N-Boc groups of NBoc-bridged calix[m]arene[n]pyridine derivatives which were prepared by a macrocyclic coupling reaction between NBoc-linked trimers and 1,3-phenylenediamine. In the solid state, calix[2]arene[2]pyridine adopted the flattened saddle conformation, while NH-bridged calix[1]arene[3]pyridine gave a slightly twisted 1,3-alternate conformer. In both cases, all NH bridges formed partial conjugation with both pyridine and benzene rings, whereas in solution they gave symmetric conformational structures in which the conjugation of bridging NH units with pyridine ring was stronger than with benzene ring. In the presence of NaH, NH-bridged calix[2]arene[2]pyridine reacted efficiently with methyl iodide and allyl bromide to afford the corresponding N-alkylated products in almost quantitative yield. Upon treatment of NH- and NMe-bridged calix[2]arene[2]pyridines with CF3CO2D and CuBr2, deuteration and bromination reactions took place selectively on the pyridine ring, producing respectively the pyridine ring-deuterated and -brominated macrocyclic products.
Synthesis, Structure, and Reactions of NH-Bridged Calix[m]arene[n]pyridines
摘要:
NH-bridged calix[1]arene[3]pyridine and calix[2]arene[2]pyridine were synthesized readily from efficient deprotection of N-Boc groups of NBoc-bridged calix[m]arene[n]pyridine derivatives which were prepared by a macrocyclic coupling reaction between NBoc-linked trimers and 1,3-phenylenediamine. In the solid state, calix[2]arene[2]pyridine adopted the flattened saddle conformation, while NH-bridged calix[1]arene[3]pyridine gave a slightly twisted 1,3-alternate conformer. In both cases, all NH bridges formed partial conjugation with both pyridine and benzene rings, whereas in solution they gave symmetric conformational structures in which the conjugation of bridging NH units with pyridine ring was stronger than with benzene ring. In the presence of NaH, NH-bridged calix[2]arene[2]pyridine reacted efficiently with methyl iodide and allyl bromide to afford the corresponding N-alkylated products in almost quantitative yield. Upon treatment of NH- and NMe-bridged calix[2]arene[2]pyridines with CF3CO2D and CuBr2, deuteration and bromination reactions took place selectively on the pyridine ring, producing respectively the pyridine ring-deuterated and -brominated macrocyclic products.
Cu(OTf)<sub>2</sub>-Catalyzed Selective Arene C–H Bond Hydroxylation and Nitration with KNO<sub>2</sub> as an Ambident <i>O</i>- and <i>N</i>-Nucleophile via a Cu(II)–Cu(III)–Cu(I) Mechanism
作者:Hu Zhang、Liang Zhao、De-Xian Wang、Mei-Xiang Wang
DOI:10.1021/ol401453f
日期:2013.8.2
Cu(OTf)2-catalyzed selective arene C–H bond hydroxylation and nitration reactions of azacalix[1]arene[3]pyridines were achieved using KNO2 as an ambident O- and N-nucleophile under very mild aerobic conditions to yield functionalized azacalixaromatics. The reaction, which selectivity between hydroxylation and nitration was modulated by the reaction medium employed, proceeded through a Cu(II)–Cu(III)–Cu(I) mechanism
Designing a Cu(II)–ArCu(II)–ArCu(III)–Cu(I) Catalytic Cycle: Cu(II)-Catalyzed Oxidative Arene C–H Bond Azidation with Air as an Oxidant under Ambient Conditions
作者:Bo Yao、Yang Liu、Liang Zhao、De-Xian Wang、Mei-Xiang Wang
DOI:10.1021/jo502115a
日期:2014.11.21
On the basis of our recent discovery of highvalent organocopper compounds, we have designed and achieved efficient copper(II)-catalyzed oxidative arene C-H bond azidation under very mild aerobic conditions by using NaN3 as an azide source. In the presence of a Cu(II) catalyst, a number of azacalix[1]arene[3]pyridines underwent directarene C-H bond cupration through an electrophilic aromatic metalation
Synthesis, Structure, and Reactions of NH-Bridged Calix[<i>m</i>]arene[<i>n</i>]pyridines
作者:Bo Yao、De-Xian Wang、Han-Yuan Gong、Zhi-Tang Huang、Mei-Xiang Wang
DOI:10.1021/jo900826n
日期:2009.8.7
NH-bridged calix[1]arene[3]pyridine and calix[2]arene[2]pyridine were synthesized readily from efficient deprotection of N-Boc groups of NBoc-bridged calix[m]arene[n]pyridine derivatives which were prepared by a macrocyclic coupling reaction between NBoc-linked trimers and 1,3-phenylenediamine. In the solid state, calix[2]arene[2]pyridine adopted the flattened saddle conformation, while NH-bridged calix[1]arene[3]pyridine gave a slightly twisted 1,3-alternate conformer. In both cases, all NH bridges formed partial conjugation with both pyridine and benzene rings, whereas in solution they gave symmetric conformational structures in which the conjugation of bridging NH units with pyridine ring was stronger than with benzene ring. In the presence of NaH, NH-bridged calix[2]arene[2]pyridine reacted efficiently with methyl iodide and allyl bromide to afford the corresponding N-alkylated products in almost quantitative yield. Upon treatment of NH- and NMe-bridged calix[2]arene[2]pyridines with CF3CO2D and CuBr2, deuteration and bromination reactions took place selectively on the pyridine ring, producing respectively the pyridine ring-deuterated and -brominated macrocyclic products.