A study of microwave-induced and standard thermal Overman rearrangement of selected allylic trichloroacetimidates 1a-1f, 6-8 to the corresponding acetamides 2a-2f, 9-11 is reported. The microwave-assisted rearrangement of trifluoroacetimidate 13 is also described. Using this methodology, an efficient access to versatile allylic trihaloacetamides building synthons was established.
syn- and anti-[Pd(eta3-allyl)] complexes. Addition of chloride triggers a true memory effect, in which the allylic terminus originally bearing the leaving group has a higher reactivity. The latter effect, termed regioretention, can be rationalized by ionization from a palladium complex bearing a chloride ion, forming an unsymmetrically substituted [Pd(eta3-allyl)] complex. DFT calculations verify that
Influences on the Regioselectivity of Palladium-Catalyzed Allylic Alkylations
作者:Uli Kazmaier、Daniel Stolz、Katja Krämer、Franz L. Zumpe
DOI:10.1002/chem.200701332
日期:2008.1.28
Chelated amino acid ester enolates are excellent nucleophiles for palladium-catalyzed allylicalkylations. These enolates react rapidly at -78 degrees C and in general without isomerization of pi-allyl palladium complexes. Therefore, they are good candidates for mechanistic studies and regioselective reactions. Terminal pi-allyl palladium complexes are preferentially attacked at the least hindered
The Role of Trichloroacetimidate To Enable Iridium-Catalyzed Regio- and Enantioselective Allylic Fluorination: A Combined Experimental and Computational Study
作者:Alexandre M. Sorlin、Jason C. Mixdorf、Madeline E. Rotella、Robert T. Martin、Osvaldo Gutierrez、Hien M. Nguyen
DOI:10.1021/jacs.9b07575
日期:2019.9.18
provides insight into the mechanism and origin of regio- and enantioselectivity of the iridium-catalyzed allylic fluorination. A synergistic computational and experimental study provides strong support for a dynamic kinetic asymmetric transformation (DYKAT) of racemic allylic trichloroacetimidate, leading to regio- and enantioselective allylic C-F bond formation. This combined study also highlights the
Synthesis of 2,3-Disubstituted Pyrroles from 3,<i>N</i>-Dilithio-<i>N</i>-(<i>tert</i>-butyldimethylsilyl)-2-buten-1-amine
作者:Madeleine A. Jacobson、Paul G. Williard
DOI:10.1021/jo015638n
日期:2002.1.1
N-(Trialkylsilyl)allylamines can be deprotonated at the cis-vinylic position to yield 3,N-dilithio-N-(trialkylsilyl)allylamines under mild conditions. N-(Trialkylsilyl)allylamines with terminal alkyl substituents were reported not to form dianions under the same conditions. During our investigations we found that N-(tert-butyldimethylsilyl)-2-buten-1-amine (1) is deprotonated under the reaction conditions