Stereoselective synthesis of trifluoromethyl-substituted 2H-furan-amines from enaminones

Abstract

A straightforward strategy for synthesis of highly functionalized trifluoromethyl 2H-furans is described.

Recent Advances in Transition‐Metal‐Catalyzed Reactions of N‐Tosylhydrazones

“…In 2020, the group of Jiang investigated a stereoselective synthesis of trifluoromethyl‐substituted 2 H ‐furan‐amines from enaminones, allowing a general approach for the introduction of CF 3 ‐groups into heterocycles (Scheme 117). [146] This reaction provides complete diastereoselectivity with regard to the CF 3 ‐bearing quaternary stereogenic center. The use of 2.6 equivalents of base were required to ensure complete carbene formation from the N ‐tosylhydrazone.…”

A Study of the Reactions of 3‐Bromopropenals with Anilines for the Synthesis of α‐Bromo Enaminones

“…5, 139.34, 139.30, 139.1, 137.9, 135.8, 135.6, 131.8, 129.5, 128.7, 128.6, 117.45, 117.43, 114.0, 107.2 5,139.5,137.9,136.4,135.5,135.2,131.8,128.7,128.6,127.4,126.5,117.2,107.1;HRMS (ESI) 3, 149.3, 141.5, 140.5, 138.1, 131.5, 130.9, 128.6, 121.7, 118.3, 111. 158.5,148.4,139.4,131.2,130.3,130.0,129.8,129.3,128.2,119.3,117.4,105.1;HRMS (ESI) 7.6 Hz,1H),2H),4H),1H),6.96 (d,J = 8.4 Hz,1H); 13 C-NMR (100 MHz, CDCl 3 ): δ 194. 5, 188.8, 141.6, 141.1, 138.6, 136.7, 136.0, 131.3, 128.7, 128.5, 122.3, 121.5, 113.2, 104.9 (d,J = 13.2 Hz,1H),2H),1H),2H),7.32 (dd,J = 1.2,8.0 Hz,1H),1H),1H),6.80 (d,J = 8.4 Hz,1H); 13 C-NMR (100 MHz, CDCl 3 ) δ 188.2, 141. 8,…”

“…3, 148.1, 142.7, 139.0, 130.8, 128.6, 128.5, 128.4, 123.8, 121.3, 113.6, 111.1, 102.3, 55.9 7.96 (brs, 1H), 7.46-7.34 (m, 5H), 6.96 (t, J = 8 Hz, 1H), 6.85 (d, J = 8 Hz, 1H), 6.53 (t, J = 8 Hz, 1H), 6.18 (d, J = 8 Hz, 1H), 3.92 (s, 3H); 13 C-NMR (100 MHz, CDCl 3 ): δ 182.6, 159. 5, 151.0, 131.1, 130.5, 130.0, 128.7, 127.3, 125.2, 122.2, 120.2, 110.7, 103.6, 55.8 (d,J = 13.6 Hz,1H),5H),3H),7.09 (t,J = 7.6 Hz,1H),6.91 (d,J = 7.6 Hz,2H); 13 C-NMR (100 MHz, CDCl 3 ): δ 188. 3, 143.5, 139.1, 138.8, 131.0, 129.9, 128.5, 128.4, 124.2, 116.5, 102.0 7, 159.9, 137.9, 130.7, 130.5, 130.4, 129.0, 128.7, 125.3, 123.5, 103. (d,J = 12.7 Hz,1H),2H),2H),J = 15.6,1.4 Hz,1H),7.03 (td,J = 15.4,0.7 Hz,1H),3H), 4.44 (q, J = 7.2 Hz, 2H), 3.89 (s, 3H), 1.44 (t, J = 7.1 Hz, 3H); 13 C-NMR (100 MHz, CDCl 3 ) δ 188.…”

“…5, 151.0, 131.1, 130.5, 130.0, 128.7, 127.3, 125.2, 122.2, 120.2, 110.7, 103.6, 55.8 (d,J = 13.6 Hz,1H),5H),3H),7.09 (t,J = 7.6 Hz,1H),6.91 (d,J = 7.6 Hz,2H); 13 C-NMR (100 MHz, CDCl 3 ): δ 188. 3, 143.5, 139.1, 138.8, 131.0, 129.9, 128.5, 128.4, 124.2, 116.5, 102.0 7, 159.9, 137.9, 130.7, 130.5, 130.4, 129.0, 128.7, 125.3, 123.5, 103. (d,J = 12.7 Hz,1H),2H),2H),J = 15.6,1.4 Hz,1H),7.03 (td,J = 15.4,0.7 Hz,1H),3H), 4.44 (q, J = 7.2 Hz, 2H), 3.89 (s, 3H), 1.44 (t, J = 7.1 Hz, 3H); 13 C-NMR (100 MHz, CDCl 3 ) δ 188. 1, 167.8, 162.3, 142.5, 141.3, 134.9, 132.2, 131.3, 131.1, 121.9, 115.3, 114.0, 113.9, 104.0, 61.8, 55.6, 14.5 7, 161.8, 158.5, 141.4, 133.0, 132.2, 131.6, 123.8, 122.5, 121.8, 118.7, 114.7, 106.3, 61.9, 55.7,14. (d,J = 12.9 Hz,1H),1H),1H),2H),7.98 (dt,J = 7.6,1.3 Hz,1H),7.69 (t,J = 7.69 Hz,1H),7.48 (td,J = 7.9,1.5 Hz,1H),7.10 (td,J = 7.6,0.8 Hz,…”

The Wonderful World of β‐Enamino Diketones Chemistry

“…The chemistry of β‐dimethylaminovinyl ketones – commonly known as β‐enaminones – has been widely explored for nearly 60 years, and the vast majority of heterocycles have been synthesized using them as starting materials. [ 1 ] Among these, azoles – such as triazolo/tetrazolo[1,5‐ a ]pyrimidines, [ 2–5 ] 1,2,3‐triazoles, [ 6 ] benzimidazoles, [ 7 ] pyrazoles, [ 8–10 ] pyrroles, [ 11,12 ] isoxazoles, [ 13,14 ] thiazoles [ 15 ] – and furans, [ 16 ] and other six‐membered heterocycles – such as quinolines, [ 17–19 ] pyridines, [ 20,21 ] chromones, [ 22 ] and oxathiines [ 23 ] – have been prepared by using β‐enaminones through formal [3+2] or [3+3] cyclocondensation or cycloaddition reactions, with a variety of reagents ( N,N‐ or N,O ‐dinucleophiles, NCN ‐dinucleophiles, etc. ), catalysts, and specific reaction conditions.…”