765915-07-9Relevant academic research and scientific papers
Gold(I)-catalyzed highly regio- and stereoselective decarboxylative amination of allylic N-tosylcarbamates via base-induced aza-Claisen rearrangement in water
Xing, Dong,Yang, Dan
supporting information; experimental part, p. 1068 - 1071 (2010/06/13)
(Figure Presented)A gold(l)-catalyzed decarboxylative animation of allylic N-tosylcarbamates via base-induced aza-Claisen rearrangement has been developed. A variety of substituted W-tosyl allylic amines were obtained In good yield, excellent regloselectlvity, and high to excellent stereoselectivity. This transformation could be performed either in H2O or In one pot directly from allylic alcohols and therefore represents an efficient and environmentally benign protocol for the synthesis of N-tosyl allylic amines.
Iterative deoxypropionate synthesis based on a copper-mediated directed allylic substitution
Breit, Bernhard,Herber, Christian
, p. 3790 - 3792 (2007/10/03)
Can't have too much of a good thing: A flexible, iterative strategy based on a highly selective copper-mediated allylic substitution makes the preparation of any desired oligo(deoxypropionate) stereoisomer possible (see scheme; RDG = reagent-directing group). This approach differs from the established enolate-alkylation methodology through the reversed polarity of the reaction partners and avoids several problems associated with the latter method.
Chiral ions in the gas phase. 1. Intramolecular racemization and isomerization of O-protonated (S)-trans-4-hexen-3-ol
Troiani, Anna,Gasparrini, Francesco,Grandinetti, Felice,Speranza, Maurizio
, p. 4525 - 4534 (2007/10/03)
The acid-catalyzed racemization and regioisomerization of (S)-trans-4- hexen-3-ol (1S) has been investigated in gaseous CH4 and C3H8 at 720 Torr and in the 40-120 °C temperature range. The contribution to the racemization and isomerization products by free 1-methyl-3-ethylallyl cations, arising from unimolecular fragmentation of excited O-protonated (S)-trans-4-hexen-3- ol (IS), was evaluated by generating them from protonation of isomeric 2,4- hexadienes and by investigating their behavior toward H218O under the same experimental conditions. The rate constant of the gas phase racemization of IS (1.4-21.3 x 106 s-1) was found to exceed that of its isomerization (1.0-9.9 x 106 s-1) over the entire temperature range. The experimental results, combined with ab initio theoretical calculations on the model [C3H5+/H2O] system, are consistent with a gas phase intramolecular 1S racemization and isomerization involving the intermediacy of structured ion- molecule complexes, wherein the H20 molecule is coplanarly coordinated to the hydrogen atoms of the 1-methyl-3-ethylallyl moiety. The rate of formation of these structured complexes, their relative stability, and the dynamics of their evolution to the racemized and isomerized products depend, in the gas phase, on the specific conformation of IS. The relevant activation parameters point to transition structures wherein a substantial fraction of the positive charge is located on the allyl moiety. The results obtained in the present gas phase investigation confirm previous indications about the occurrence and the role of intimate ion-molecule pairs in acid-catalyzed racemization and isomerization of optically active alcohols, including allylic alcohols, in solution.
