A novel binaphthylamine auxiliary for asymmetric imidate claisen rearrangement
作者:Benno Hungerhoff、Peter Metz
DOI:10.1016/s0040-4020(99)00978-3
日期:1999.12
The enantiomerically pure methyl substituted binaphthylamine 7 has been prepared via a regioselective directed ortho-metallation of the methoxy substituted binaphthyl carboxylic acid 5 as the key step and used as an auxiliary for asymmetric imidate Claisenrearrangement. Excellent auxiliary induction as well as simple (anti/syn) diastereoselection was achieved.
Claisen rearrangement of N-silyl ketene N,O-acetals generated from allyl N-phenylimidates
作者:Peter Metz、Cornelia Linz
DOI:10.1016/s0040-4020(01)89670-8
日期:1994.3
O-acetals 5 which undergo a Claisenrearrangement to yield γ,δ-unsaturated anilides 3 after hydrolytic work-up. The temperature for the rearregement step is dependent on the nature of the substituent R2 in 5. Ketene acetals 5 with R2 = H rearrage readily at room temperature, while heating at 130 °C is required if R2≠H. The degree of simple diastereoselection attainable for the conversion of 1 to 3 is strongly
Efficient synthesis of 3-substituted lactams using meerwein eschenmoser claisen [3,3] sigmatropic rearrangements.
作者:Brian Coates、David Montgomery、Paul J. Stevenson
DOI:10.1016/s0040-4039(00)79904-7
日期:1991.8
3-Allyl substituted five, six and seven membered ring lactams are readily available in good yields and reasonable selectivity by a formal Meerwein Eschenmoser Claisen [3,3] rearrangement, using the readily available N,N-dialkylalkoxymethylene iminium salts and lithium alkoxides derived from allyl alcohols.
Highly Enantioselective Claisen Rearrangement of Imidates Derived from Primary Allyl Alcohols
作者:Peter Metz、Benno Hungerhoff
DOI:10.1021/jo970123a
日期:1997.6.1
A highly enantioselective and diastereoselective Claisen rearrangement of N-arylimidates derivedfrom an axially chiral binaphthylamine auxiliary is reported. Upon deprotonation of the imidates with lithium diethylamide, the resultant azaenolates rearrange at 0 degrees C to give anti alpha,beta-disubstituted, gamma,delta-unsaturated N-binaphthyl amides. A iodolactonization/zinc reduction sequence readily
The enantioselective fluoroacetamide acetal claisen rearrangements of N-fluoroacetyl-trans-(2R,5R)-2,5-dimethylpyrrolidine
作者:Takashi Yamazaki、John T Welch、Janet S Plummer、Rayomand H Gimi
DOI:10.1016/s0040-4039(00)92145-2
日期:1991.1
Opticallyactive monofluorinated amides were prepared via the amide acetal Claisenrearrangement and the establishment of the absolute stereochemistry of the rearranged products proved that the chiral auxiliary directed the approach of the crotyl fragment to the Si face of the (E)-N,O-ketene acetal. The general utility of this type of rearrangement is also discussed.