Reactions of 3-aryl-1-(trifluoromethyl)prop-2-yn-1-iminium salts with 1,3-dienes and styrenes

• Thomas Schneider,
• Michael Keim,
• Bianca Seitz and
• Gerhard Maas

Beilstein J. Org. Chem. 2020, 16, 2064–2072, doi:10.3762/bjoc.16.173

• ], trifluoroacetaldehyde hemiaminals [16][17][18], N,O-acetals [19] and N,N-acetals [20], 2-(trifluoromethyl)-1,3-oxazolidines [21], and N-(tert-butylsulfinyl)trifluoroacetaldimine [11][22]. Other synthetic approaches to α-CF3-substituted amines include nucleophilic trifluoromethylation strategies [17], such as the

2-Phenyl- tetrahydropyrimidine- 4(1H)-ones – cyclic benzaldehyde aminals as precursors for functionalised β²-amino acids

• Markus Nahrwold,
• Arvydas Stončius,
• Anna Penner,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2009, 5, No. 43, doi:10.3762/bjoc.5.43

• . In the course of this study, an L-asparagine derivative was condensed with benzaldehyde and subsequently converted to orthogonally protected (R)-β2-homoaspartate. Keywords: β2-amino acids; cyclocondensation; diastereoselective alkylation; N,N-acetals; peptidomimetics; ring opening; self-regeneration

• , this novel concept was applied to synthesise orthogonally protected (R)-β2-homoaspartate by means of “self-regeneration of stereogenic centres” (SRS). Asparagine derived benzaldehyde N,N-acetals comparable to 9 have formerly been used as α-alkyl-asparagine precursors [39] and furthermore have been