α-Bromodiazoacetamides – a new class of diazo compounds for catalyst-free, ambient temperature intramolecular C–H insertion reactions

• Åsmund Kaupang and
• Tore Bonge-Hansen

Beilstein J. Org. Chem. 2013, 9, 1407–1413, doi:10.3762/bjoc.9.157

• /or conformational flexibility of the C–H fragment is of importance. The α-bromo-β-lactam 5b and its α-chloro-analogue have previously been prepared by Johansson et al. in 61% [45] and 53–54% yield [53][54], respectively, by the thermolysis of α-dihalo(phenylmercury)acetamides in bromobenzene under

Organic synthesis using (diacetoxyiodo)benzene (DIB): Unexpected and novel oxidation of 3-oxo-butanamides to 2,2-dihalo-N-phenylacetamides

• Wei-Bing Liu,
• Cui Chen,
• Qing Zhang and
• Zhi-Bo Zhu

Beilstein J. Org. Chem. 2012, 8, 344–348, doi:10.3762/bjoc.8.38

• chemical synthesis. This protocol not only adds a new aspect to reactions that use other hypervalent iodine reagents but also provides a wide space for the synthesis of disubstituted acetamides. Keywords: cleavage of carbon–carbon bond; (diacetoxyiodo)benzene; difunctionalized acetamides; novel oxidation

• application of this protocol to synthesize difunctionalized acetamides from 3-oxo-butanamides is reported here for the first time. In order to probe the mechanism of this transformation, we employed 2,2-dichloro-3-oxo-N-phenylbutanamide (1m) and 2,2-dibromo-3-oxo-N-phenylbutanamide (1n) as reactants under

• to the synthesis of other difunctionalized acetamides and detailed investigations of the reaction mechanism are in progress. Synthesis of 1-carbamoyl-2-oxopropyl acetates. Synthesis of 2,2-dihalo-N-phenylacetamides. Synthesis of dichloroacetamides. Reagents and conditions: 1 (1.0 mmol), dioxane (2 mL

Synthetic approaches to multifunctional indenes

• Neus Mesquida,
• Sara López-Pérez,
• Immaculada Dinarès and
• Ermitas Alcalde

Beilstein J. Org. Chem. 2011, 7, 1739–1744, doi:10.3762/bjoc.7.204

• -indenyl)acetamides as key intermediates. Although several multistep synthetic approaches can be applied to obtain these advanced intermediates, we describe herein their preparation by an aldol-type reaction between 5-nitroindan-1-ones and the lithium salt of N,N-disubstituted acetamides, followed

• nitroindanones 5 and the lithium salt of ethyl acetate [18]. The present work deals with the alternative synthetic route B, which relies on the direct formation of the advanced (3-indenyl)acetamides 3 from nitroindanone 5 and shortens the synthetic sequence to two steps. The aldol-type reaction of indanone 5

• with the lithium salts of different N,N-disubstituted acetamides, followed immediately by dehydration afforded the (3-indenyl)acetamides 3. The success of this route, however, depends on two main factors: (i) The nature of the lithiated base used to deprotonate acetamides in order to form lithium

Fine-tuning alkyne cycloadditions: Insights into photochemistry responsible for the double-strand DNA cleavage via structural perturbations in diaryl alkyne conjugates

• Wang-Yong Yang,
• Samantha A. Marrone,
• Nalisha Minors,
• Diego A. R. Zorio and
• Igor V. Alabugin

Beilstein J. Org. Chem. 2011, 7, 813–823, doi:10.3762/bjoc.7.93

• acetamides. The significant protecting effect of the hydroxyl radical and singlet oxygen scavengers to DNA cleavage was shown only with m-lysine conjugate. All three isomeric lysine conjugates inhibited human melanoma cell growth under photoactivation: The p-conjugate had the lowest CC50 (50% cell

• substituent in different positions (o-, m-, and p-) relative to the alkyne (acetamides in Figure 4). Such variations in the substitution pattern are known to impose significant effects on photochemical reactivity [56][57]. Reactions with cyclohexadiene were used to probe the properties of the triplet excited

• follow the order of the photocycloaddition of their acetamides. Although the m-substituted acetylene was more photoreactive toward 1,4-CHD, the corresponding conjugate 6 produced less DNA cleavage than conjugate 1. This suggests that either the difference in DNA binding overshadows the intrinsic