Studies of the selective O-alkylation and dealkylation of flavonoids. 10. Selective demethylation of 7-hydroxy-3,5,8-trimethoxyflavones with anhydrous aluminum halide in acetonitrile or ether
Synthesis of Aryl Ethers from Aromatic Carboxylic Acids
作者:Lukas Gooßen、Sukalyan Bhadra、Wojciech Dzik
DOI:10.1055/s-0033-1339470
日期:——
meta-substituted carboxylates are converted into para-substituted alkoxyarenes and vice versa. The combined processes provide a convenient synthetic entry to the important class of aromatic ethers from widely available carboxylicacids. A silver/copper bimetallic catalyst system promotes the decarboxylative Chan–Evans–Lam alkoxylation of ortho-substituted aromatic carboxylate salts with tetraalkyl orthosilicates
Decarboxylative Etherification of Aromatic Carboxylic Acids
作者:Sukalyan Bhadra、Wojciech I. Dzik、Lukas J. Goossen
DOI:10.1021/ja304539j
日期:2012.6.20
Decarboxylative Chan-Evans-Lam-type couplings are presented as a new strategy for the regiospecific construction of diaryl and alkyl aryl ethers starting from easily available aromatic carboxylic acids. They allow converting various aromaticcarboxylatesalts into the corresponding aryl ethers by reaction with alkyl orthosilicates or aryl borates, under aerobic conditions in the presence of silver
Surfactant-mediated solvent-free dealkylative cleavage of ethers and esters and trans-alkylation under neutral conditions
作者:Apurba Bhattacharya、Nitin C. Patel、Tomas Vasques、Ritesh Tichkule、Gaurang Parmar、Jiejun Wu
DOI:10.1016/j.tetlet.2005.11.048
日期:2006.1
A simple, surfactant-mediated, one-pot, solvent-free dealkylative cleavage of aryl ethers and esters followed by subsequent optional trans-alkylation under essentially neutral conditions has been developed.
Doubly Regioselective C–H Hydroarylation of Unsymmetrical Alkynes Using Carboxylates as Deciduous Directing Groups
作者:Agostino Biafora、Bilal A. Khan、Janet Bahri、Joachim M. Hewer、Lukas J. Goossen
DOI:10.1021/acs.orglett.7b00300
日期:2017.3.3
carbonate, and mesitoic acid efficiently promotes the doubly regioselectiveC–H hydroarylation of unsymmetrical alkynes. The process involves carboxylate-directed ortho-C–H bond activation followed by regioselective addition to the alkyne C–C triple bond with concerted decarboxylation. This action of the carboxylate as a deciduous directing group ensures exclusive monovinylation with high selectivity
由[(C 6 Me 6)RuCl 2 ] 2,碳酸钾/碳酸胍和甲基磺酸组成的催化剂体系有效地促进了不对称炔烃的双区域选择性C–H加氢芳基化。该过程涉及羧基定向的邻-C-H键活化,然后区域选择性地添加到炔烃C-C三键中,并伴有协同的脱羧作用。羧酸盐作为落叶指导基团的这种作用确保了对(E)-1,2-二芳基烯烃具有高选择性的排他性单乙烯基化。
Studies on Tyrosinase Inhibitory and Antioxidant Activities of Benzoic Acid Derivatives Containing Kojic Acid Moiety
作者:Ho-Sik Rho、Chang-Seok Lee、Soo-Mi Ahn、Yong-Deog Hong、Song-Seok Shin、Young-Ho Park、Soo-Nam Park
DOI:10.5012/bkcs.2011.32.12.4411
日期:2011.12.20
Although compound 2 has a kojicacid moiety for chelation to copper in the active site of tyrosinase, tyrosinase inhibitory activity is not found. We also synthesized a benzoate ester of kojicacid without an adamantane moiety and investigated its tyrosinase inhibitory and radical scavenging activities. Scheme 1 shows the synthetic pathways for the benzoate ester of kojicacid. The reaction of kojic acid