In the Baylis-Hillman reaction of N-benzylidene-4-methylbenzenesulfonamide with methylvinylketone (MVK), we found that, in the presence of a catlytic amount of DMAP, PPh^3 or DABCO as Lewis base, jthe Baylis-Hillman reaction can be greatly accelerated to give the normmal Baylis-Hillman adducts 1 in good or jvery jhigh yields. However, with Pbu^3 as a Lewis base, the abnormal Baylis-Hillman adducts
The aza‐Morita‐Baylis–Hillman (aza‐MBH) reaction has been studied in a variety of solvents, a selection of imine substrates and with various combinations of PPh3 and para‐nitrophenol as the catalyst system. The measured kinetic data indicates that the effects of solvent and protic co‐catalyst are strongly interdependent. These results are most easily reconciled with a mechanistic model involving the
已在多种溶剂,多种亚胺底物以及PPh 3和对硝基苯酚的各种组合作为催化剂体系中研究了aza-Morita-Baylis-Hillman(aza-MBH)反应。测得的动力学数据表明,溶剂和质子助催化剂的作用密切相关。这些结果最容易与涉及两性离子中间体在催化循环中可逆质子化的机理模型相吻合,这也得到31 P NMR光谱学和量子化学研究的支持。
Catalyst-Free Alkylation of Sulfinic Acids with Sulfonamides via sp<sup>3</sup> C−N Bond Cleavage at Room Temperature
alkylation of sulfinicacids with sulfonamides has been developed via sp3 C−N bond cleavage at room temperature. In the absence of external catalysts and additives, a wide variety of N-benzylic and N-allylic sulfonamides couple with sulfinicacids to give structurally diversified sulfones in moderate to excellent yields. Furthermore, the reaction of N-(2-acyl)allylic sulfonamides with sulfinicacids provides
Polymer-Supported Lewis Bases for the Baylis–Hillman Reaction
作者:Jin-Wen Huang、Min Shi
DOI:10.1002/adsc.200303072
日期:2003.8
of polymer-supported Lewisbases such as PEG4600-(PPh2)2 and poly(DMAP) in the Baylis–Hillman reactions of N-tosylimines (ArCHNTs) 1 or the corresponding arenecarbaldehydes with α,β-unsaturated ketones has been investigated. The corresponding Baylis–Hillman adducts are obtained in good yields. The polymer-supported Lewisbases can be easily recovered by filtration and the Lewis base PEG4600-(PPh2)2
Switchable pyrrole-based hydrogen bonding motif in enantioselective trifunctional organocatalysis
作者:Sviatoslav S. Eliseenko、Fei Liu
DOI:10.1016/j.tet.2018.12.016
日期:2019.1
Pyrroles are versatile chemical motifs for molecular recognition or ligand design but their utility as catalytic components are underexplored. We incorporated a pyrrole motif into our acid-switchable, MAP-based trifunctional organocatalytic system. The switching-on of this system by an external Brønstedacid, 3-methyl benzoic acid, presented proficient catalysis in both aza-Morita–Baylis–Hillman (MBH