An expedient and new synthesis of pyrrolo[1,2-b]pyridazine derivatives

• Rajeshwar Reddy Sagyam,
• Ravinder Buchikonda,
• Jaya Prakash Pitta,
• Himabindu Vurimidi,
• Pratap Reddy Padi and
• Mahesh Reddy Ghanta

Beilstein J. Org. Chem. 2009, 5, No. 66, doi:10.3762/bjoc.5.66

• cycloaddition of dimethyl acetylenedicarboxylate to the Reissert compound of pyridazine [20], the 1,3-dipolar cycloaddition of pyridazinium dichloromethylide generated by the carbene method [21], and the cycloaddition of alkylidene cyclopropane derivatives to pyridazine in the presence of Pd(PPh3)4 [22

Mitomycins syntheses: a recent update

• Jean-Christophe Andrez

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

• the planned construction of the aziridine by tandem SN2 displacement. Exploiting the facial selectivity of compound 38, the direct introduction of an aziridine equivalent was attempted by 1,3-dipolar cycloaddition of an alkyl azide. As Frank noted, cycloaddition of azides to 3H-pyrrolo [1,2-a]indoles

Dimerization of propargyl and homopropargyl 6-azido- 6-deoxy- glycosides upon 1,3-dipolar cycloaddition

• Nikolas Pietrzik,
• Daniel Schmollinger and
• Thomas Ziegler

Beilstein J. Org. Chem. 2008, 4, No. 30, doi:10.3762/bjoc.4.30

• Nikolas Pietrzik Daniel Schmollinger Thomas Ziegler Institute of Organic Chemistry, University of Tuebingen, Auf der Morgenstelle 18, 72076 Tuebingen, Germany. 10.3762/bjoc.4.30 Abstract Copper-catalyzed, thermal or microwave promoted 1,3-dipolar cycloaddition (Click Reaction) of 2-propynyl and 3

• -triazoles which are known to be easily generated through a copper-catalyzed 1,3-dipolar cycloaddition of an organic azide and an alkynyl derivative (Click Reaction) [5][6][7]. For review articles on copper-catalyzed Click Reactions see references [8][9][10][11]. Recently, we applied this approach to a

• series of 1,2,3-triazole containing per-O-acetyl-glycosides which were prepared by copper-catalyzed 1,3-dipolar cycloaddition either between fully acetylated propargyl 1-thio-glycosides and t-butyl (S)-4-azido-3-fluorenylmethyloxycarbamido-butyrate or between Fmoc-L-Asp(OtBu)-propargyl amide and 2,3,4,6

Synthesis of new triazole- based trifluoromethyl scaffolds

• Michela Martinelli,
• Thierry Milcent,
• Sandrine Ongeri and
• Benoit Crousse

Beilstein J. Org. Chem. 2008, 4, No. 19, doi:10.3762/bjoc.4.19

• derivatives to afford 1,4-disubstituted 1,2,3-triazoles through a Huisgen 1,3-dipolar cycloaddition. The reaction is catalyzed by a Cu(I) species in acetonitrile, and the corresponding products are obtained in good yields. This process thus offers an entry to new trifluoromethyl peptidomimetics as interesting

• trifluoromethyl groups on the conformation of peptidomimetics, we decided to explore the preparation of trifluoromethyl triazole derivatives. Herein we turn our attention to the synthesis of new triazoles from trifluoromethyl propargylamines using the Huisgen 1,3-dipolar cycloaddition [27][28][29]. Results and

• Discussion The synthetic approach depicted in Scheme 1 shows that the desired compounds could be easily obtained via a 1,3-dipolar cycloaddition from the corresponding propargylamines which are obtained using an efficient procedure from the trifluoromethyl imines previously described by our group [30][31][32

Synthesis of densely functionalized enantiopure indolizidines by ring- closing metathesis (RCM) of hydroxylamines from carbohydrate- derived nitrones

• Marco Bonanni,
• Marco Marradi,
• Francesca Cardona,
• Stefano Cicchi and
• Andrea Goti

Beilstein J. Org. Chem. 2007, 3, No. 44, doi:10.1186/1860-5397-3-44

• . [5][6][7][8][9][10][11][12][13][14][15][16][17][18] We accomplished the total syntheses of some indolizidine alkaloids and of several non-natural analogues employing chiral nitrones as key intermediates, either as dipolarophiles in 1,3-dipolar cycloaddition chemistry [19][20] or as electrophiles in

Aroylketene dithioacetal chemistry: facile synthesis of 4-aroyl- 3-methylsulfanyl- 2-tosylpyrroles from aroylketene dithioacetals and TosMIC

• H. Surya Prakash Rao and
• S. Sivakumar

Beilstein J. Org. Chem. 2007, 3, No. 31, doi:10.1186/1860-5397-3-31

• heterocyclic systems, examples of their participation in the cycloaddition reactions are rare. In continuation of our interest on ketene acetals [5][6][7] we considered that 1,3-dipolar cycloaddition of the anion generated from the von Leusen's reagent (p-tolylsulfonyl)methyl isocyanide (TosMIC) 2 to AKDTAs 1