TY - JOUR
T1 - Stereocontrolled Total Synthesis of (–)-Stemaphylline.
AU - Varela, Ana
AU - Garve, Lennart K. B.
AU - Leonori, Daniele
AU - Aggarwal, Varinder K.
PY - 2017/1/18
Y1 - 2017/1/18
N2 - Homologation of readily available α-boryl pyrrolidines with metal carbenoids is especially challenging even when good leaving groups (Cl−) are employed. By performing a solvent switch from Et2O to CHCl3, efficient 1,2-metalate rearrangement of the intermediate boronate occurs with both halide and ester leaving groups. The methodology was used in the total synthesis of the Stemona alkaloid (−)-stemaphylline in just 11 steps (longest linear sequence), with high stereocontrol (>20:1 d.r.) and 11 % overall yield. The synthesis also features a late-stage lithiation–borylation reaction with a tertiary amine containing carbenoid.
AB - Homologation of readily available α-boryl pyrrolidines with metal carbenoids is especially challenging even when good leaving groups (Cl−) are employed. By performing a solvent switch from Et2O to CHCl3, efficient 1,2-metalate rearrangement of the intermediate boronate occurs with both halide and ester leaving groups. The methodology was used in the total synthesis of the Stemona alkaloid (−)-stemaphylline in just 11 steps (longest linear sequence), with high stereocontrol (>20:1 d.r.) and 11 % overall yield. The synthesis also features a late-stage lithiation–borylation reaction with a tertiary amine containing carbenoid.
U2 - 10.1002/ange.201611273
DO - 10.1002/ange.201611273
M3 - Article
SN - 1433-7851
JO - Angewandte Chemie - International Edition
JF - Angewandte Chemie - International Edition
ER -