Intermolecular domino Michael/aldol reactions of α,β-unsaturated esters, aromatic aldehydes, and various nucleophiles promoted with a catalytic amount of a guanidine base in DMSO
作者:Shunya Morita、Tomoyuki Yoshimura、Jun-ichi Matsuo
DOI:10.1016/j.tet.2021.132329
日期:2021.8
3-tetramethylguanidine, BTMG) effectively catalyzed intermolecular three-component reactions of α,β-unsaturated esters, aldehydes, and carbon-, sulfur-, or nitrogen-pronucleophiles to give three-component addition products with the formation of two new σ-bonds: pronucleophiles and aldehydes reacted with α,β-unsaturated esters at their β-positions and α-positions, respectively. Mechanism studies suggested that
在 DMSO 中,催化量的巴顿碱 (2- t-丁基-1,1,3,3-四甲基胍,BTMG)有效催化α,β-不饱和酯、醛和碳-、硫-或氮-亲核试剂的分子间三组分反应,得到三组分加成产物形成两个新的 σ 键:亲核试剂和醛分别在其 β 位和 α 位与 α,β-不饱和酯反应。机理研究表明,这些反应是通过第一次分子间迈克尔加成的阴离子亲核试剂与催化量的 BTMG 形成的阴离子亲核试剂进行的,然后是瞬时酯烯醇化物的分子间醛醇反应,即使在超过化学计量的酸性亲核试剂存在下。