54589-55-8

Upstream product

• 124-63-0 methanesulfonyl chloride 
• 34905-02-7 [4-(prop-2-yn-1-yloxy)phenyl]methanol 
• 61747-71-5 2-propynyl 4-(2-propynyloxy)benzoate 
• 623-05-2 (4-hydroxyphenyl)methanol 
• 99-96-7 4-hydroxy-benzoic acid 

Downstream Products

• 54758-84-8 C₂₂H₁₈O₂S 
• 54759-16-9 3-(4-Phenoxy-phenoxymethyl)-benzoic acid prop-2-ynyl ester 
• 54759-19-2 C₂₂H₁₈O₃ 

Relevant academic research and scientific papers

Bioorthogonal Uncaging of the Active Metabolite of Irinotecan by Palladium-Functionalized Microdevices

SN-38, the active metabolite of irinotecan, is released upon liver hydrolysis to mediate potent antitumor activity. Systemic exposure to SN-38, however, also leads to serious side effects. To reduce systemic toxicity by controlling where and when SN-38 is generated, a new prodrug was specifically designed to be metabolically stable and undergo rapid palladium-mediated activation. Blocking the phenolic OH of SN-38 with a 2,6-bis(propargyloxy)benzyl group led to significant reduction of cytotoxic activity (up to 44-fold). Anticancer properties were swiftly restored in the presence of heterogeneous palladium (Pd) catalysts to kill colorectal cancer and glioma cells, proving the efficacy of this novel masking strategy for aromatic hydroxyls. Combination with a Pd-activated 5FU prodrug augmented the antiproliferative potency of the treatment, while displaying no activity in the absence of the Pd source, which illustrates the benefit of achieving controlled release of multiple approved therapeutics—sequentially or simultaneously—by the same bioorthogonal catalyst to increase anticancer activity.

Selective upper rim functionalization and lower rim bridge building with calix[4]arenes and calix[6]arenes

Selective upper rim functionalization of calix[6]arenes has been achieved by selective lower rim benzoylation at the 1,2,4,5 positions followed by AlCl3-induced removal of the tert-butyl groups of the unesterified aryl residues and introduction of various functionalities into the vacated para positions, including bromo (5), dialkylamino, (7-11) cyanomethyl (12), and (propargyloxy)methyl (13) groups. Lower rim bridge building has been achieved via oxidative coupling reactions between the aryne moieties of calix[4]arenes and calix[6]arenes in which O-benzyl groups carry one (from 23 and 24) or two (from 25) propargyloxy residues. In the calix[4]arene series both a single-spanned (32) and a double-spanned (33) double-cavity calixarene were obtained. In the calix[6]arene series only a single-spanned double cavity calixarene (36) could be characterized.