A New Co2(CO)8-Mediated Tandem [5 + 1]/[2 + 2 + 1]-Cycloaddition Reaction: A One-Pot Synthesis of Tricyclic δ-Lactones from cis-Epoxy Ene-ynes
摘要:
In the presence of Co2(CO)8 and CO, cis-epoxyalkynes bearing a tether olefin undergo a tandem [5 + 1]/[2 + 2 + 1]-cycloaddition to give tricyclic delta-lactones efficiently in a one-pot operation. The reaction mechanism is proposed to involve a cobalt-coordinated cyclic allene species.
A New Co2(CO)8-Mediated Tandem [5 + 1]/[2 + 2 + 1]-Cycloaddition Reaction: A One-Pot Synthesis of Tricyclic δ-Lactones from cis-Epoxy Ene-ynes
摘要:
In the presence of Co2(CO)8 and CO, cis-epoxyalkynes bearing a tether olefin undergo a tandem [5 + 1]/[2 + 2 + 1]-cycloaddition to give tricyclic delta-lactones efficiently in a one-pot operation. The reaction mechanism is proposed to involve a cobalt-coordinated cyclic allene species.
[4 + 2]-Annulation of MBH-Acetates of Acetylenic Aldehydes with Imidazoles/Benzimidazoles To Access Imidazo[1,2-<i>a</i>]pyridines/Benzimidazo[1,2-<i>a</i>]pyridines
作者:Chada Raji Reddy、Amarender Goud Burra
DOI:10.1021/acs.joc.9b01118
日期:2019.7.19
developed to construct diversely substituted imidazo[1,2-a]pyridines and benzimidazo[1,2-a]pyridines in good to excellent yield. The advantage of this unique [4 + 2]-annulation lies in the employment of readily accessible starting materials, Morita–Baylis–Hillman acetates of acetylenic aldehydes as C4 synthons, and simple imidazoles or benzimidazoles as C2 synthons.