Gold-catalyzed propargylic substitutions: Scope and synthetic developments

• Olivier Debleds,
• Eric Gayon,
• Emmanuel Vrancken and
• Jean-Marc Campagne

Beilstein J. Org. Chem. 2011, 7, 866–877, doi:10.3762/bjoc.7.99

• and oxime cyclization gave, in a one-pot sequence, the corresponding isoxazoles 40 in good yields (Scheme 20) [86]. Conclusion In conclusion, we have developed gold(III)-catalyzed direct propargylic (allylic, benzylic) substitutions which have proved efficient with a great number of nucleophiles under

An overview of the key routes to the best selling 5-membered ring heterocyclic pharmaceuticals

• Marcus Baumann,
• Ian R. Baxendale,
• Steven V. Ley and
• Nikzad Nikbin

Beilstein J. Org. Chem. 2011, 7, 442–495, doi:10.3762/bjoc.7.57

• ] (Figure 3). Structurally, this medication consists of a complex pyrrole-substituted 2-indolinone core which can be prepared by a late stage aldol condensation between a 2-indolinone fragment 42 with the corresponding pyrrole aldehyde 41 (Scheme 7). The oxime functionality in compound 38, which is obtained

• oxime 38 under reductive conditions. Deprotection and decarboxylation of the remaining tert-butyl ester produces the desired pyrrole intermediate, which upon treatment with Vilsmeier reagent undergoes a formal acylation. This product is not isolated but reacted directly with 41 in an aldol condensation

Palladium- and copper-mediated N-aryl bond formation reactions for the synthesis of biological active compounds

• Carolin Fischer and
• Burkhard Koenig

Beilstein J. Org. Chem. 2011, 7, 59–74, doi:10.3762/bjoc.7.10

• -carboxylate (39) and 2-bromobenzaldehyde O-benzyl oxime (38), and only a moderate yield (53%) using CuI [59]. Targeting the same product, Ma et al. used copper catalysis some years previously. The coupling of 1,4-diiodobenzene (41) and (S)-ethyl 3-amino-6-hydroxyhexanoate (42), and subsequent esterification

A surprising new route to 4-nitro-3-phenylisoxazole

• Henning Hopf,
• Aboul-fetouh E. Mourad and
• Peter G. Jones

Beilstein J. Org. Chem. 2010, 6, No. 68, doi:10.3762/bjoc.6.68

• include the reaction of aromatic α,β-unsaturated aldehydes with dinitrogen trioxide [11][12], the nitration of 3-phenyl-isoxazole [13][14], and the hydrolysis of methyl 4-nitro-3-phenyl-5-carboxylate, obtained by reaction of α-nitroacetophenone oxime and methoxalyl chloride [15]. In conclusion, a very

Mitomycins syntheses: a recent update

• Jean-Christophe Andrez

Beilstein J. Org. Chem. 2009, 5, No. 33, doi:10.3762/bjoc.5.33

• activity [136]. Starting with the tricyclic ketone 181 [137][138] a low yielding bromination reaction was undertaken followed by an acetate displacement of the resulting α-bromoketone to give 182 (Scheme 50). The amine was introduced by formation of an oxime followed by catalytic hydrogenation in the

The role of an aromatic group in remote chiral induction during conjugate addition of α-sulfonylallylic carbanions to ethyl crotonate

• Shlomo Levinger,
• Ranjeet Nair and
• Alfred Hassner

Beilstein J. Org. Chem. 2008, 4, No. 32, doi:10.3762/bjoc.4.32

• for orthogonality between the planar function and the aromatic nucleus in the nitrogen derivatives of 9-acylanthracenes has been corroborated spectroscopically (lack of conjugation in the semicarbazide and the oxime). Furthermore, steric hindrance to attack at the cyano group of anthracene-9

Sordarin, an antifungal agent with a unique mode of action

• Huan Liang

Beilstein J. Org. Chem. 2008, 4, No. 31, doi:10.3762/bjoc.4.31

• abovementioned pathogens with respect to the first GM generation. Toxicity studies on mammalian (including human) cell lines revealed a lower in vitro toxicity than the clinically used compound, amphotericin B. Oxime 57, isoxazoline 58 and isoxazole 59 derivatives were prepared in the Bristol-Myers Squibb

Synthesis of 2-substituted 9-oxa-guanines {5-aminooxazolo[5,4-d]pyrimidin- 7(6H)-ones} and 9-oxa-2-thio- xanthines {5-mercaptooxazolo[5,4-d]pyrimidin- 7(6H)-ones}

• Subrata Mandal,
• Wen Tai Li,
• Yan Bai,
• Jon D. Robertus and
• Sean M. Kerwin

Beilstein J. Org. Chem. 2008, 4, No. 26, doi:10.3762/bjoc.4.26

• prepared from the (acylamino)cyanoacetates 5b,c, which in turn were derived from ethyl cyanoglyoxylate oxime (4) by reduction followed by acylation by isobutyric anhydride or azidoacetyl chloride (Figure 3). Reaction of the aminooxazoles 3b,c with benzoylisothiocyanate afforded the thioureas 6b,c. Direct

Novel base catalysed rearrangement of sultone oximes to 1,2-benzisoxazole- 3-methane sulfonate derivatives

• Veera Reddy Arava,
• Udaya Bhaskara Rao Siripalli,
• Vaishali Nadkarni and
• Rajendiran Chinnapillai

Beilstein J. Org. Chem. 2007, 3, No. 20, doi:10.1186/1860-5397-3-20

• from the spectral data and physical properties (Table 2). Although conversion of sultone oxime 5 into 3-alkyl-1,2-benzisoxazole derivatives [2][3] proved to be difficult using NaOH and KOH under different conditions, it was found that the rearrangement proceeded smoothly with either NaOH in ethylene