Synthesis of Allyl 2-Dialkylamino-4-pentenoates and Their Analogs via Stevens Rearrangement
摘要:
Stevens rearrangement of ammonium salts containing an allyloxycarbonylmethyl group in benzene in the presence of sodium phenoxide yields allyl 2-dialkylamino-4-pentenoates. The rearrangement in the presence of sodium methoxide is accompanied by transesterification to afford methyl 2-dialkylamino-4-pentenoates.
Dynamics and a Unified Understanding of Competitive [2,3]- and [1,2]-Sigmatropic Rearrangements Based on a Study of Ammonium Ylides
作者:Bibaswan Biswas、Sean C. Collins、Daniel A. Singleton
DOI:10.1021/ja4128289
日期:2014.3.12
The [2,3]- and [1,2]-sigmatropic rearrangements of ammoniumylides are studied by a combination of experimental, standard computational, and dynamic trajectory methods. The mixture of concerted [2,3] rearrangement and bond cleavage observed experimentally is accounted for by the outcome of trajectories passing through the formal [2,3] rearrangement transition state. In this way the bond cleavage is
N-Alkylation and [2,3]-sigmatropic rearrangement of N-allyl α-amino esters
作者:Iain Coldham、Mark L. Middleton、Philip L. Taylor
DOI:10.1039/a705550a
日期:——
N-Alkylation of N-allyl α-amino esters and [2,3]-Stevens rearrangement occur in one pot on warming in the solvent DMF, with the bases K2CO3 and DBU; this in situ formation of the quaternary ammonium salts and rearrangement of the subsequent ylides gives N,N-dialkylated allyl glycine derivatives.
Stevens rearrangement of ammonium salts containing 2-propynyloxy or tert-butoxycarbonylmethyl groups
作者:A. B. Babakhanyan、S. A. Ovakimyan、V. V. Grigoryan、S. T. Kocharyan
DOI:10.1007/s11176-005-0143-z
日期:2004.8
transesterification. The salts containing a tert -butoxycarbonylmethyl group undergo almost no transesterification under the action of sodium methylate. The tert -butyl fragment in the ester group of the salt with a benzyl group exerts a fairly strong effect on the regiochemistry of the rearrangement and on the prototropic isomerization of the 3,2-Stevens rearrangement of the salts with 2-butynyl or 3-phenyl-2-propynyl
The present invention provides inventive stitched polypeptides, pharmaceutical compositions thereof, and methods of making and using inventive stitched polypeptides.