Stereocontrolled synthesis of tetrasubstituted chiral allenes by a Michael Addition of ortho-sulfinylated benzyl-propargylic carbanions
作者:Juan A. Venegas-Nava、Francisco Yuste、Rubén Sánchez-Obregón
DOI:10.1016/j.tetlet.2021.153425
日期:2021.11
A transition metal free synthesis of tetrasubstituted allenes is presented, the reaction of α,β-unsaturated esters with ortho-sulfinylated benzyl-propargylic carbanions yields the tetrasubstituted chiral allene in good yields (44–61%) and with good isomeric ratios (75:25 to 90:10).
Stereocontrolled Addition of Scrambling <i>ortho</i>-Sulfinyl Carbanions: Easy Access to Homopropargylamines and α-Allenylamines
作者:Balú Cruz-Delgado、Ricardo I. Rodríguez、Anielka Rosado-Abón、Rubén Sánchez-Obregón、Francisco Yuste、José Alemán
DOI:10.1021/acs.orglett.0c00625
日期:2020.3.20
An unprecedented behavior of ortho-sulfinylpropargyl carbanions in the presence of optically active sulfinylimines affords two different families of compounds: this peculiar chemodivergency is importantly affected by the nature of the employed base, and assisted by the configuration of the electrophile, displaying no alteration in the stereocontrol of both reactions. alpha-Allenylamines are formed exclusively, using R-sulfinyl aldimines as electrophiles, while homopropargylamines result when S-sulfinyl aldimines are employed.