Iridium-catalyzed asymmetric ring-opening reactions of oxabicyclic alkenes with secondary amine nucleophiles

• Dingqiao Yang,
• Ping Hu,
• Yuhua Long,
• Yujuan Wu,
• Heping Zeng,
• Hui Wang and
• Xiongjun Zuo

Beilstein J. Org. Chem. 2009, 5, No. 53, doi:10.3762/bjoc.5.53

• -catalyzed asymmetric ring-opening of oxabenzonorbornadiene with a wide range of nucleophiles including thiols [10], phenols [11], organoboronic acids [12][13], dialkylzincs [14][15], carboxylates [16], sulfur nucleophiles [17], and various amines [18][19]. In addition to rhodium catalysts, other transition

An easy synthesis of 5-functionally substituted ethyl 4-amino- 1-aryl- pyrazolo- 3-carboxylates: interesting precursors to sildenafil analogues

• Said A. S. Ghozlan,
• Khadija O. Badahdah and
• Ismail A. Abdelhamid

Beilstein J. Org. Chem. 2007, 3, No. 15, doi:10.1186/1860-5397-3-15

• arylhydrazononitriles 1a-c are valuable precursors to 4-amino-5-substituted-1-aryl-1H-pyrazole-3-carboxylic acid ethyl ester which can be used for preparation of sildenafil analogues. synthesis of Ethyl 4-amino-5-substituted-1-aryl-1H-pyrazole-3-carboxylates (4) Reactivity of pyrazole 4b with phenylisothiocyanate and

Crystal engineering of analogous and homologous organic compounds: hydrogen bonding patterns in trimethoprim hydrogen phthalate and trimethoprim hydrogen adipate

• Packianathan Thomas Muthiah,
• Savarimuthu Francis,
• Urszula Rychlewska and
• Beata Warżajtis

Beilstein J. Org. Chem. 2006, 2, No. 8, doi:10.1186/1860-5397-2-8

• motifs in organic crystal structures [25]. This has also been observed in the crystal structures of trimethoprim carboxylates such as trimethoprim salicylate monohydrate [26], trimethoprim acetate [9], trimethoprim salicylate methanol solvate [19], trimethoprim benzoate [10] etc,. This fork-like hydrogen