- Diazo- And transition-metal-free C-H insertion: A direct synthesis of β-lactams
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Carbene intermediates are very useful species for a range of reactions including C-H insertions and cycloadditions. They are most commonly generated by metal-catalyzed release of nitrogen gas from diazo precursors. Herein, we present a novel C-H insertion
- Gomes, Luis F. R.,Veiros, Ls F.,Maulide, Nuno,Afonso, Carlos A. M.
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supporting information
p. 1449 - 1453
(2015/01/30)
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- Ruthenium catalysts for carbenoid intramolecular C-H insertion of 2-diazoacetoacetamides and diazomalonic ester amides
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The intramolecular carbenoid C-H insertion of 2-diazoacetoacetamides, leading to γ- and/or β-lactams, is catalyzed effectively by dinuclear Ru(I,I) complexes of the type [Ru2(μ-L1)2(CO)4L22], where L1 is a bidentate bridging acetate, calix[4]arenedicarboxylate, saccharinate or 6-chloropyridin-2-olate ligand. By comparison with rhodium catalysts, namely dirhodium tetraacetate and dirhodium calix[4]arenedicarboxylate complexes, product yields are similarly high and the regioselectivity of the insertion reaction is the same. Surprisingly, even the ruthenium(0) cluster Ru3(CO)12 was found to be an effective catalyst for carbenoid C-H insertion of 2-diazoacetoacetamides and also of some diazoacetamides. In terms of diastereoselectivity, trans-isomers of β- and γ-lactams are obtained. However, the β-lactam obtained from diazomalonic ester amide 2 yields the cis-isomer stereoselectively, which slowly rearranges to the trans-isomer.
- Grohmann, Markus,Maas, Gerhard
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p. 12172 - 12178
(2008/02/10)
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- Construction of β-Lactams by Highly Selective Intramolecular C-H Insertion from Rhodium(II) Carboxylate Catalyzed Reactions of Diazoacetamides
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Intramolecular β-C-H insertion occurs in high yield and with exceptional selectivity in rhodium(II) carboxylate catalyzed decompositions of diazoacetamides
- Doyle, Michael P.,Shanklin, Michael S.,Pho, Su-Min Oon Hoan Q.,Heide, Feike R. van der,Veal, William R.
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p. 3384 - 3386
(2007/10/02)
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- 1,3-Oxazines and Related Compounds. XIV. Facile Synthesis of 2,3,6-Trisubstituted 2,3-Dihydro-1,3-oxazine-5-carboxilyc Acids and 1,4-Disubstituted 3-Acyl-β-lactams from Acyl Meldrum's Acids and Schiff Bases
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Simple preparation of 2,3,6trisubstituted 2,3-dihydro-1,3-oxazine-5-carboxylic acids (4) and 1,4-disubstituted 3-acyl-β-lactams (5) from acyl Meldrum's acids and Schiff bases were carried out.2,3-Disubstituted 5-acyl-3,4,5,6-tetrahydro-2H-1,3-oxazine-4,6-
- Yamamoto, Yutaka,Watanabe, Yokiyoshi
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p. 1871 - 1879
(2007/10/02)
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- Reaction of 2,2,6-trimethyl-1,3-dioxin-4-one with Imines
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The reaction of 2,2,6-trimethyl-1,3-dioxin-4-one (diketene-acetone adduct) (1) with imines was investigated.Heating of the adduct 1 with N-(1-phenylethylidene)aniline (6a) gave 6-methyl-1,2-diphenyl-4(1H)-pyridone 7a.Similar treatment of N-benzylideneanil
- Masayuki, Sato,Ogasawara, Hiromichi,Yoshizumi, Eriko,Kato, Tetsuzo
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p. 1902 - 1909
(2007/10/02)
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- REACTION OF 2,2,6-TRIMETHYL-1,3-DIOXIN-4-ONE WITH SCHIFF BASE
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Heating of 2,2,6-trimethyl-1,3-dioxin-4-one (1) with Schiff bases (2a-f) gave 2,3-disubstituted 6-methyl-1,3-oxazin-4-ones (4a-f).N-Benzylidene-tert-butylamine, under the similar condition, gave acetoacetamide derivative (3g) and acetylazetidinone derivative (5).
- Sato, Masayuki,Ogasawara, Hiromichi,Yoshizumi, Eriko,Kato, Tetsuzo
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p. 297 - 300
(2007/10/02)
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