Cooperativity in Diiron(III)porphyrin Dication Diradical-Catalyzed Oxa-Diels–Alder Reactions: Spectroscopic and Mechanistic Insights
作者:Sabyasachi Sarkar、Pallavi Sarkar、Deepannita Samanta、Swapan K Pati、Sankar Prasad Rath
DOI:10.1021/acscatal.2c02479
日期:2022.8.5
electron-deficient aldehydes such as glyoxylicacid derivatives or activated electron-rich 1,3-dienes such as Danishefsky’s, Brassard’s, or Rawal’s diene. The robust catalyst exhibited high functional group tolerance. The computational studies corroborated the detailed spectroscopic investigation, which focused on the pivotal roles played by the metalion as the Lewis acidic center in combination with counteranions
Cationic iron(III) porphyrin was found to be an efficient catalyst for the highly chemoselective hetero-Diels Alder-type reaction of aldehydes with 1,3-dienes. The catalyzed process did not require the use of electron-deficient aldehydes such as glyoxylic acid derivatives or activated electron-rich 1,3-dienes such as Danishefslcy's diene and Rawal's diene. The high functional group tolerance and robustness of the catalyst were demonstrated. Further, the potential utility of the catalyst was demonstrated by performing the cycloaddition in the presence of water and by carrying out cycloaddition of an unactivated ketone such as cyclohexanone with a diene.
Carbocation Catalysis: Oxa-Diels-Alder Reactions of Unactivated Aldehydes and Simple Dienes
作者:Mahmoud Abd El Aleem Ali Ali El Remaily、Veluru Ramesh Naidu、Shengjun Ni、Johan Franzén
DOI:10.1002/ejoc.201501112
日期:2015.10
organocatalyst is demonstrated in the oxa-Diels-Alder reaction of various unactivated aromatic and aliphatic aldehydes and simple unactivated dienes, such as isoprene and 2,3-dimethylbutadiene. The transformation proceeds smoothly to give 3,6-dihydropyrane adducts in high to moderate yields with catalyst loadings down to 1.0 mol-% under mild reaction conditions. In contrast to most previously reported