Transition Metal-Free Cyclization of N-Boc-N-propargylenamines
摘要:
An efficient method for the synthesis of multi-substituted pyrroles was developed using basic cyclization of readily accessible N-Boc-N-propargylenamines. Despite the basic conditions, cleavage of the N-Boc group occurred easily. The process was rapid and afforded N-H-pyrroles with wide functional group tolerance in high yields.
A transition-metal-free synthesis of pyridine derivatives by 6-endo-dig cyclization of N-propargyl enamines was developed. This method is environmentally friendly and is a high atom economy reaction that is easily accessed to provide pyridine derivatives in moderate to good yield by heating N-propargyl enamines in solvent without additives. The total synthesis of onychine was achieved in 51% yield