The reaction of cis- or trans-5-isopropenyl-2-methyl-2-cyclohexenyl diethyl phosphate (1) with Me2AlX (X=OPh, SPh, NHPh) in hexane results in substitution of the –O–PO(OEt)2 group with X under predominant inversion. In contrast, treatment of cis- or trans-1 with trialkylaluminum produces predominantly the allyl-nonallyl couplingproducts of the same (thermodynamically more stable) configuration. Similar
Oritani, Takayuki; Yamashita, Kyohei, Agricultural and Biological Chemistry, 1980, vol. 44, # 11, p. 2637 - 2642
作者:Oritani, Takayuki、Yamashita, Kyohei
DOI:——
日期:——
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.