Silver Tetrafluoroborate-Catalyzed Oxa-Diels-Alder Reaction Between Electrically Neutral Dienes and Aldehydes
作者:Xiaodong Zou、Lizheng Yang、Xiangli Liu、Hao Sun、Hongjian Lu
DOI:10.1002/adsc.201500487
日期:2015.10.12
Chemoselective oxa-Diels–Alder reactionsbetween electrically neutral 1,3-dienes and various aldehydes were achieved using the commercially available silver tetrafluoroborate (AgBF4) as catalyst. This catalytic process has high functional group tolerance. Heteroatoms at the β-position of the aryl aldehydes can greatly promote the reactivity of the substrates even with heterocyclic aldehydes that were
Iron Corrole-catalyzed [4 + 2] Cycloaddition of Dienes and Aldehydes
作者:Toru Kuwano、Takuya Kurahashi、Seijiro Matsubara
DOI:10.1246/cl.130672
日期:2013.10.5
We have developed cationic iron(IV) corrole-catalyzed formal hetero-Diels–Alder reaction of aldehydes with dienes, which opens the way for divergent synthesis of pyrans. The potential utility of the catalyst was also demonstrated by carrying out cycloaddition of α,β-unsaturated aldehyde with a diene to give pyran selectively. Furthermore, the catalytic reactivity of iron corrole complex on the cycloaddition was determined by comparing that of iron porphyrin complex.
2-alkylidenecyclohexanone from 3-oxymethyl-2-siloxy-1,3-butadienes, which can be prepared from Baylis-Hillman adducts, and alpha,beta-unsaturated ketones is described. The process involves two mechanistically distinct reactions, (4+2) cycloaddition and elimination. Both of these reactions are catalyzed by Tf(2)NH.
Regio-, Chemo-, and Enantioselective Ni-Catalyzed Hydrocyanation of 1,3-Dienes
作者:Rongrong Yu、Yidan Xing、Xianjie Fang
DOI:10.1021/acs.orglett.0c04133
日期:2021.2.5
A regio-, chemo-, and enantioselective nickel-catalyzed hydrocyanation of 1,3-dienes is reported. The key to the success of this asymmetric transformation is the use of a specific multichiral diphosphite ligand. In addition to aryl-substituted 1,3-dienes, highly challenging aliphatic 1,3-diene substrates can also be preferentially converted to the corresponding 1,2-adducts in decent yields with the
The conjugateaddition of Grignard reagent (2) onto 1-α,β-unsaturated)acyl 3,5-dimethylpyrazole (1) was enantioselectively catalyzed by the copper complex from cuprous compounds and 3-phenyl-l-mentho-pyrazole (3).