Cuts both ways: The title reaction consists of an addition/cyclization/dehydration sequence and affords the biologically important chiral 3,5‐diaryl‐5‐(trifluoromethyl)‐2‐isoxazolines 1 in excellent yields with high ee values. The flexibility of accessing either the S or R enantiomers of the products has been achieved by the appropriate choice of phase‐transfer catalyst (2).
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