CuCl₂-catalyzed highly stereoselective and chemoselective reduction of alkynyl amides into α,β-unsaturated amides using silanes as hydrogen donors

Abstract

A CuH-catalyzed Z-selective partial reduction of alkynyl amides to afford α,β-unsaturated amides using silane as the hydrogen donor is developed. A broad scope of alkynyl amides is accommodated, affording alkenyl amides with high stereoselectivity and excellent yields.

Isomerization of E-Cinnamamides into Z-Cinnamamides Using a Recycling Photoreactor

“…Finally, 10 mg of E - 1c was injected into the recycling photoreactor. Consequently, Z - 1c 18 was accumulated in a similar manner to 1b over 10 cycles, giving a yield of 68% with a Z / E ratio of >99:1 ( Table 3 , entry 4; Figures S18 and S19 ).…”

Electrophilic Sulfenylation/Cyclization of N‐Aryl and N‐Benzyl Propynamides: Synthesis of Sulfenyl Quinolinones and 3H‐Benzo[c]azepin‐3‐ones

“…The authors have cited additional references within the Supporting Information. [22][23][24][25][26][27][28][29][30][31]…”

Stereoselective Semi‐Hydrogenations of Alkynes by First‐Row (3d) Transition Metal Catalysts

“…Examples with their respective copper catalyst, ligand, and reaction conditions are given in Table 6 with the appropriate literature reference. A special case of silane‐mediated semi‐hydrogenations has been reported by Duan et al., who developed a protocol for the conversion of alkynyl amides to Z ‐configurated α,β‐unsaturated amides [113] . Specifically, an excess of Me(EtO) 2 SiH is used in combination with 10 mol% of CuCl 2 and dppf in the presence of excess LiOMe in THF.…”

“…A special case of silane‐mediated semi‐hydrogenations has been reported by Duan et al., who developed a protocol for the conversion of alkynyl amides to Z ‐configurated α,β‐unsaturated amides. [113] Specifically, an excess of Me(EtO) 2 SiH is used in combination with 10 mol% of CuCl 2 and dppf in the presence of excess LiOMe in THF. At room temperature, a multitude of (hetero)aryl‐substituted alkynyl amides is converted to the ( Z )‐alkene within 8 h in good to excellent yields.…”