Joyasawal, SipakMa, DonghuiDoyle, Michael P.2021-06-242021-06-242021-06-09Molecules 26 (12): 3520 (2021)https://hdl.handle.net/20.500.12588/631A substituted donor–acceptor cyclobutenecarboxamide is synthesized with modest enantiocontrol through a chiral copper(I) complex catalyzed [3 + 1]-cycloaddition reaction of α-acyl diphenylsulfur ylides with 3-siloxy-2-diazo-3-butenamides. With a methyl substituent on the 4- position of the 3-butenamide, the cis-vicinal-3,4-disubstituted cyclobutenecarboxamide is formed with >20:1 diastereocontrol. Donor-acceptor 3-methyl-2-siloxycyclopropenecarboxamide is rapidly formed from the reactant enoldiazoamide and undergoes catalytic ring opening to give only the Z-γ-substituted metallo-enolcarbene. Elimination from 3-siloxy-2-diazo-3-pentenamide to form the conjugated 3-siloxy-2,4-pentadienamide is competitive but minimized at low temperature.Attribution 4.0 United Stateshttps://creativecommons.org/licenses/by/4.0/donor-acceptor cyclobutenecarboxamide[3 + 1]-cycloaddition reaction3-siloxy-2-diazo3-butenamidesZ-γ-substituted metallo-enolcarbenebox ligandscopper(I)Article2021-06-24