139371-98-5Relevant articles and documents
Facile access to 3-allyl- and 3-benzyl-Δ3-cephems through reductive addition/cyclization of allenecarboxylate with allylic and benzylic halides in an [NiCl2(bipy)]/PbBr2/Al redox system
Tanaka, Hideo,Sumida, Shin-Ichi,Sorajo, Kouichi,Kameyama, Yutaka,Torii, Sigeru
, p. 637 - 642 (1997)
Sequential reductive addition/cyclization of the allenecarboxylate 1, derived from penicillin G, with allylic and benzylic halides is successfully achieved by the aid of a three-metal redox system consisting of aluminium metal (2.5 molar equiv.) and catal
A Facile Access to 3-Allyl- and 3-Benzyl-3-cephems via Reductive Addition/Cyclization of Allenecarboxylate with Allyl and Benzyl Halides in an Al/Pb/Ni Redox System
Tanaka, Hideo,Sumida, Shin-ichi,Sorajo, Kouichi,Torii, Sigeru
, p. 1461 - 1462 (1994)
A sequential reductive addition/cyclization reaction of allenecarboxylate, derived from penicillin G, with allyl and benzyl halides was successfully performed by the aid of aluminium metal and catalytic amounts of PbBr2 and to afford 3-allyl-
Conversion of cephem into penam/penem through sequential ring-opening/recyclization in an Al/BiCl3/AlCl3 system
Tanaka, Hideo,Tokumaru, Yoshihisa,Kameyama, Yutaka,Torii, Sigeru
, p. 1221 - 1222 (1997)
A sequential reductive ring-opening/recyclization reaction of 3-substituted Δ3-cephems into 2-exco-methylenepenams and/or 2-methylpenems was successfully performed by treatment with Al/BiCl3/AlCl3 in NMP (N-methyl-2-pyrrol
Process for producing exo-methylenepenam compounds
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Page column 6, (2008/06/13)
The present invention is directed to a process for preparing an exo-methylenepenam compound wherein a cephem compound is reduced with a metal having a standard oxidation-reduction potential of up to ?0.3 (V/SCE) in an amount of at least one mole per mole
Synthesis of 2-exo-methylenepenam and 3-chloro-Δ3-cephem through a sequential reductive 1,2-elimination/S-S bond fission or chloride ion-addition/cyclization of 3,4-disubstituted 2-butenoates in metal salt/metal combinations
Tanaka,Sumida,Nishioka,Kobayashi,Tokumaru,Kameyama,Torii
, p. 3610 - 3617 (2007/10/03)
Synthesis of 2-exo-methylenepenam 1 through a sequential reductive 1,2-elimination/S-S bond fission/cyclization of 6 was performed by treatment with a PbBr2/Al (or a BiCl3/Al) combination in DMF, while that of 3-chloro-Δ3-cephem 2 through reductive 1,2-elimination/chloride ion-addition/cyclization was attained by use of an AlCl3/Al combination in N-methylpyrrolidone (NMP). The selective transformation of 6 to the allenecarboxylate 3 was also achieved by treatment with an AlBr3/Al combination in NMP. Cyclic voltammograms of 3,4-disubstituted 2-[2-oxo-3-(phenylacetamido)-4-[(phenylsulfonyl)thio]azetidin-1-yl]-2- butenoates (6) exhibit two irreversible reduction peaks responsible for reductive 1,2-elimination of the 3,4-disubstituted 2-butenoate moiety (at less negative potential) and for reductive S-S bond fission of the (phenylsulfonyl)thio moiety, suggesting that the reductive 1,2-elimination of 6 leading to allenecarboxylate 3 would occur prior to the reductive S-S bond cleavage.
Synthesis of 2-exo-Methylenepennam by Reductive 1,2-Elimination and S-S Bond Fission in a PbBr2/Al Bimetal System
Tanaka, Hideo,Nishioka, Youichi,Kameyama, Yutaka,Sumida, Shin-ichi,Matsuura, Hiroyuki,Torii, Sigeru
, p. 709 - 710 (2007/10/03)
A convenient synthesis of 2-exo-methylenepenam was performed by reductive elimination of 3,4-disubstituted chlorine atom(s) and/or a triflate moiety and S-S bond fission of the phenylsulfonylthio group of p-methoxybenzyl 3,4-dichloro or 4-chloro-3-(triflu
A convenient synthesis of 2-exo-methylene penam, a potent intermediate for new β-lactam antibiotics synthesis
Tanaka, Hideo,Kameyama, Yutaka,Kosaka, Atsuko,Yamauchi, Takahito,Torii, Sigeru
, p. 7445 - 7448 (2007/10/02)
A convenient synthesis of 2-exo-methylene penams 1 was performed by transformation of thiazoline-azetidinones, derived from penicillin G, through intramolecular Michael addition. Manipulation of the exo-methylene moiety of 1 opened new entries to 2-oxopenam and 2β-thiomethyl substituted penams, respectively.