- Synthesis of γ,δ-unsaturated quaternary α-alkylamino acids using umpolung reaction and Claisen rearrangement
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A new synthesis of γ,δ-unsaturated quaternary α-amino acid derivatives was developed utilizing N-alkylation and Claisen rearrangement of allyl α-iminocarboxylates.
- Mizota, Isao,Tanaka, Katsuki,Shimizu, Makoto
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supporting information; experimental part
p. 1847 - 1850
(2012/05/04)
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- Biodegradable cross-linked poly(amino alcohol esters) based on LMW PEI for gene delivery
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Polyethylenimine (PEI, especially with Mw of 25000) has been known as an efficient gene carrier and a gold standard of gene transfection due to its high transfection efficiency (TE). However, high concomitant cytotoxicity limited the application of PEI. In this report, several cationic polymers derived from low molecular weight (LMW) PEI (Mw 600) linked with diglycidyl adipate (DA-PEI) or its analogs (diglycidyl succinate, DS-PEI and diglycidyl oxalate, DO-PEI; D-PEIs for all 3 polymers) were prepared and characterized. GPC gave Mws of DA-PEI, DS-PEI and DO-PEI as 6861, 16015 and 35281, respectively. Moreover, degradation of the ester-containing DS-PEI was also confirmed by GPC. In addition, hydroxyls in these polymers could improve their water solubility. These polymers exhibited good ability to condense plasmid DNA into nanoparticles with the size of 120-250 nm. ζ-potentials of the polyplexes were found to be around +10-20 mV under weight ratios (polymer/DNA) from 0.5 to 32. Agarose gel retardation showed that DNA could be released from the polyplexes after being pre-incubated for 30 h. In vitro experiments were carried out and it was found that DS-PEI showed about 5 times of TE compared to that of the PEI/DNA polyplex under a weight ratio of 1 in A549 cells. Meanwhile, the cytotoxicity of D-PEIs assayed by MTT is lower than that of 25 kDa PEI in HEK293 cells. These results suggested that this series of PEI derivatives would be promising non-viral biodegradable vectors for gene delivery. The Royal Society of Chemistry.
- Li, Shuo,Wang, Yu,Zhang, Ji,Yang, Wei-Han,Dai, Zhen-Hua,Zhu, Wen,Yu, Xiao-Qi
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experimental part
p. 1254 - 1262
(2012/03/10)
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- New stereospecific synthesis of Tesaglitazar and Navaglitazar precursors
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A new synthetic route of to pharmaceutical intermediates (S)-1a-b and (S)-14 is reported. The reaction pathway is based on the baker's yeast-mediated reduction of the α-alkoxy cinnamaldehydes 9a-c to give the corresponding (S)-alcohols in good yields and
- Brenna, Elisabetta,Fuganti, Claudio,Gatti, Francesco G.,Parmeggiani, Fabio
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experimental part
p. 2694 - 2698
(2010/04/29)
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- Novel syntheses of oxamides, oxamates and oxalates from diisopropenyl oxalate
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Diisopropenyl oxalate, obtained by catalytic addition of oxalic acid to propyne, is a useful reagent for the access to a variety of α-dicarbonyl compounds such as oxamides, oxamates and oxalates, under very mild conditions.
- Neveux, Muriel,Bruneau, Christian,Lecolier, Serge,Dixneuf, Pierre H.
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p. 2629 - 2640
(2007/10/02)
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- Method of preparation of oxalic acid esters and amides
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A new process is described for the preparation of oxalic acid esters and amides of general formula (I) STR1 wherein Z designates an --OR or --NR1 R2 group, wherein R represents substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, or aryl-alkyl, R1 is hydrogen or substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, or aryl-alkyl, R2 represents substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, or aryl-alkyl, or R1 and R2 taken together with the adjacent nitrogen atom represent a saturated 5-, 6-, 7-, or 8-membered heterocyclic ring, which may contain an additional heteroatom selected from --O--, --S--, and --N(H, Alkyl)--, and optionally bear one or more alkyl or alkenyl substituents, and Z1 designates an --OR or --NR1 R2 group, wherein R, R1, and R2 are as defined before, or a group --NHCOCH3, which comprises the base-catalysed reaction of diacetyloxamide with an alcohol ROH or/and an amine HNR1 R2. The compounds of formula (I) have many industrial utilities, mainly as intermediates and stabilizers in the polymer field.
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- New method of preparation of oxalic acid esters and amides
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A new process is described for the preparation of oxalic acid esters and amides of general formula (I) Z- wherein, Z designates an -OR or -NR1R2 group, wherein R represents substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, or aryl-alkyl, R1 is hydrogen or substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, or aryl-alkyl, R2 represents substituted or unsubstituted alkyl, alkenyl, cycloalkyl, aryl, or aryl-alkyl, or R1 and R2 taken together with the adjacent nitrogen atom represent a saturated 5-, 6-, 7-, or 8-membered heterocyclic ring, which may contain an additional heteroatom selected from -O-, -S-, and -N(H, Alkyl)-, and optionally bear one or more alkyl or alkenyl substituents, and, Z1 designates an -OR or -NR1R2 group, wherein R, R1, and R2 are as defined before, or a group -NHCOCH3, which comprises the base-catalysed reaction of diacetyloxamide with an alcohol ROH or/and an amine HNR1R2. The compounds of formula (I) have many industrial utilities, mainly as intermediates and stabilizers in the polymer field.
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