Study on the coupling of acyclic esters with alkenes – the synthesis of 2-(2-hydroxyalkyl)cyclopropanols via cascade cyclization using allylsamarium bromide
Cobalt(II)-Catalyzed Conversion of Allylic Alcohols/Acetates to Allylic Amides in the Presence of Nitriles
作者:Manoj Mukhopadhyay、M. Madhava Reddy、G. C. Maikap、Javed Iqbal
DOI:10.1021/jo00114a013
日期:1995.5
Various secondary allylic alcohols or their acetates and tertiary allylic alcohols can be converted to the corresponding transposed allylic amides in the presence of a catalytic quantity of cobalt(II) chloride and acetic anhydride in acetonitrile. Tertiary alcohols undergo complete rearrangement whereas secondary ones afford a mixture of regioisomers. Moderate yields of amides are also obtained by reacting acrylonitrile with secondary alcohols in 1,2-dichloroethane. The presence of acetic anhydride or acetic acid is crucial to the formation of amides as the absence of the former affords no amides and the allylic alcohols are mainly recovered as regioisomeric mixtures. The regioselectivity during amide formation can be enhanced by using cobalt complexes 14-16 in acetic acid medium. Some preliminary studies indicate that these reactions are proceeding via an pi-allyl complex or tight ion pair rather than a [3,3] sigmatropic rearrangement of acetamidate obtained in a Pinner reaction.
Duveen; Kenyon, Bulletin de la Societe Chimique de France, 1938, vol. <5>5, p. 708
作者:Duveen、Kenyon
DOI:——
日期:——
Study on the coupling of acyclic esters with alkenes – the synthesis of 2-(2-hydroxyalkyl)cyclopropanols via cascade cyclization using allylsamarium bromide
作者:Yawei Tu、Liejin Zhou、Ruifeng Yin、Xin Lv、Robert A. Flowers II、Kimberly A. Choquette、Huili Liu、Qingsheng Niu、Xiaoxia Wang
DOI:10.1039/c2cc34630c
日期:——
The radical cyclization between aliphatic acyclic esters and alkenes was achieved unprecedentedly in the presence of allylsamarium bromide with HMPA and H2O as additives. The cascade radical cyclizationâring-openingâanionic cyclization allowed facile and efficient access to 2-(2-hydroxyalkyl)cyclopropanols from readily available materials.