Base-Catalyzed Stereospecific Isomerization of Electron-Deficient Allylic Alcohols and Ethers through Ion-Pairing
作者:Samuel Martinez-Erro、Amparo Sanz-Marco、Antonio Bermejo Gómez、Ana Vázquez-Romero、Mårten S. G. Ahlquist、Belén Martín-Matute
DOI:10.1021/jacs.6b08350
日期:2016.10.12
between an allylic anion and the conjugate acid of the base results in efficient transfer of chirality. Through this mechanism, stereochemical information contained in the allylic alcohols is transferred to the ketone products. The stereospecific isomerization is also applicable for the first time to allylicethers, yielding synthetically valuable enantioenriched (up to 97% ee) enol ethers.
Enantioselective Synthesis of Trifluoromethylated Tertiary Thioethers through Organocatalytic Sulfa-Michael Addition of Thiols to β-Trifluoromethyl β,β-Disubstituted Enones
作者:Fu-Xue Chen、Yao-Feng Wang、Shaoxiang Wu、Pran Karmaker、Muhammad Sohail、Qi Wang
DOI:10.1055/s-0034-1380138
日期:——
Abstract An organocatalyticasymmetric sulfa-Michael addition of thiols to β-trifluoromethyl β,β-disubstituted (E)-enones in the presence of 10 mol% of a cinchona alkaloid-derived thiourea catalyst provides direct and simple access to chiraltrifluoromethyl tertiary thioethers in high yields and up to 76% ee. An organocatalyticasymmetric sulfa-Michael addition of thiols to β-trifluoromethyl β,β-disubstituted
Ether way: The cinchona‐alkaloid‐catalyzed title reaction was achieved in high yields with high to excellent ee values for the first time, and affords key intermediates for the biologically important 2 having a trifluoromethylated all‐carbon quaternary chiral center. Ether‐type catalysts (1) are more efficient in this transformation than the conventional hydroxy analogues.
Synthesis of α,γ-Chiral Trifluoromethylated Amines through the Stereospecific Isomerization of α-Chiral Allylic Amines
作者:Víctor García-Vázquez、Pablo Martínez-Pardo、Alexandru Postole、A. Ken Inge、Belén Martín-Matute
DOI:10.1021/acs.orglett.2c01436
日期:2022.6.3
imine/enamine intermediates, leading to γ-trifluoromethylated aliphatic amines with two noncontiguous stereogenic centers, in excellent yields and high diastereo- and enantioselectivities. This approach has been used with primaryamine substrates. This approach also provides a new synthetic pathway to chiral trifluoromethylated scaffolds, of importance in medicinal chemistry. Additionally, a gram-scale reaction