30924-93-7Relevant articles and documents
Diazaphosphinyl radical-catalyzed deoxygenation of α-carboxy ketones: A new protocol for chemo-selective C-O bond scission: Via mechanism regulation
Cheng, Jin-Pei,Yang, Jin-Dong,Zhang, Jingjing
, p. 8476 - 8481 (2020/09/07)
C-O bond cleavage is often a key process in defunctionalization of organic compounds as well as in degradation of natural polymers. However, it seldom occurs regioselectively for different types of C-O bonds under metal-free mild conditions. Here we report a facile chemo-selective cleavage of the α-C-O bonds in α-carboxy ketones by commercially available pinacolborane under the catalysis of diazaphosphinane based on a mechanism switch strategy. This new reaction features high efficiency, low cost and good group-tolerance, and is also amenable to catalytic deprotection of desyl-protected carboxylic acids and amino acids. Mechanistic studies indicated an electron-transfer-initiated radical process, underlining two crucial steps: (1) the initiator azodiisobutyronitrile switches originally hydridic reduction to kinetically more accessible electron reduction; and (2) the catalytic phosphorus species upconverts weakly reducing pinacolborane into strongly reducing diazaphosphinane. This journal is
Ready protease-catalyzed synthesis of carbohydrate-amino acid conjugates.
Boyer,Stanchev,Fairbanks,Davis
, p. 1908 - 1909 (2007/10/03)
The protease-catalyzed synthesis of amino acid est-carbohydrate conjugates as glycopeptide analogues has been achieved in a highly regioselective and carbohydrate-specific manner using amino acid vinyl ester acyl donors and minimally or completely unprotected carbohydrate acyl acceptors, which together probed active sites of proteases to reveal yield efficiencies that are modulated by the carbohydrate C-2 substitutent, and that may be exploited to allow selective one-pot syntheses.
A study of the delivery-targeting concept applied to antineoplastic drugs active on human osteosarcoma. I. Synthesis and biological activity in nude mice carrying human osteosarcoma xenografts of gem-bisphosphonic methotrexate analogues
Sturtz,Appere,Breistol,Fodstad,Schwartsmann,Hendriks
, p. 825 - 833 (2007/10/02)
With the aim of verifying the concept of osteotic vectorisation, synthesis of three methotrexate (MTX) gem-diphosphonic analogues (compounds A, B and C) was performed. These molecules were tested on BALB/c and NIH III mice previously grafted with subcutaneous implants of OHS, TTX p7 and/or TTX p11 human osteosarcoma cell lines. Antineoplasic activity of compound B and C (active compounds) was compared to the activity for MTX alone and to activity of compound A (inactive compound). Compounds B and C exhibited an increased antineoplasic activity compared to MTX alone and to compound A. At equimolar doses, compound B was found to be 5-6-fold more active than MTX given alone. We have discussed the concept of osteotic vectorisation of compound B, which could be regarded as a prodrug.
