Long-range diastereoselectivity in Ugi reactions of 2-substituted dihydrobenzoxazepines

• Luca Banfi,
• Andrea Basso,
• Valentina Cerulli,
• Valeria Rocca and
• Renata Riva

Beilstein J. Org. Chem. 2011, 7, 976–979, doi:10.3762/bjoc.7.109

• Luca Banfi Andrea Basso Valentina Cerulli Valeria Rocca Renata Riva Department of Chemistry and Industrial Chemistry, University of Genova, I-16146 Genova, Italy 10.3762/bjoc.7.109 Abstract The Ugi reaction of 2-substituted dihydrobenzoxazepines was found to proceed with unexpectedly good

• diastereoselectivitiy (diastereoisomeric ratios up to 9:1), despite the large distance between the pre-existing stereogenic centre and the newly generated one. This result represents the first good 1,4 asymmetric induction in an Ugi reaction as well as the first example of diastereoselective Ugi reaction of seven

• membered cyclic imines. It allows the diversity-oriented synthesis of various tetrahydro[f][1,4]benzoxazepines. Keywords: benzoxazepines; cyclic imines; long range stereoinduction; multicomponent reactions; Ugi reaction; Introduction The Ugi reaction is probably the most renowned and widely used

Synthesis of dihydrophenanthridines by a sequence of Ugi-4CR and palladium- catalyzed intramolecular C-H functionalization

• Florence Bonnaterre,
• Michèle Bois-Choussy and
• Jieping Zhu

Beilstein J. Org. Chem. 2008, 4, No. 10, doi:10.3762/bjoc.4.10

• -functionalization reaction has proven to be an efficient strategy to increase the skeleton diversity. Results The Ugi reaction of an o-iodobenzaldehyde (2), an aniline (3), an isocyanide (4), and a carboxylic acid (5) afforded α-acetamido-α-phenylacetamide (6) in good to excellent yields. The palladium-catalyzed

• . Introduction Multicomponent reactions (MCRs) offer a unique way to generate efficiently libraries of complex molecules with high degree of diversity [1][2]. Among them, the Ugi four component reaction (Ugi-4CR) is without doubt one of the most powerful transformations that has been extensively investigated for

• the past twenty years [3]. In order to further increase its versatility and the complexity-generating power, a variety of reaction types have been associated with Ugi-4CRs for the synthesis of medicinally relevant heterocycles [4][5][6]. Using this MCR/post functionalization strategy, we have