Asymmetric Mannich reactions of (S)-N-tert-butylsulfinyl-3,3,3-trifluoroacetaldimines with yne nucleophiles

• Ziyi Li,
• Li Wang,
• Yunqi Huang,
• Haibo Mei,
• Hiroyuki Konno,
• Hiroki Moriwaki,
• Vadim A. Soloshonok and
• Jianlin Han

Beilstein J. Org. Chem. 2020, 16, 2671–2678, doi:10.3762/bjoc.16.217

• , Paseo Manuel Lardizábal 3, 20018 San Sebastián, Spain IKERBASQUE, Basque Foundation for Science, Alameda Urquijo 36-5, Plaza Bizkaia, 48011 Bilbao, Spain 10.3762/bjoc.16.217 Abstract In the present work, arylethynes were studied as new C-nucleophiles in the asymmetric Mannich addition reactions with (S

• afford diastereomerically pure compounds. The purified Mannich addition products were deprotected to give the target enantiomerically pure trifluoromethylpropargylamines. A mechanistic rationale for the observed stereochemical outcome is discussed. Keywords: arylethynes; asymmetric Mannich reaction; C

• optimized reaction conditions in hand, we examined the generality of these asymmetric Mannich reactions by using various arylethynes 2 (Scheme 2). Under standard reaction conditions, all the tested substrates worked well to generate the corresponding Mannich adducts in moderate to good yields. In particular