100518-76-1Relevant articles and documents
Phosphine-catalyzed domino reactions: A route to functionalized bicyclic skeletons
Li, Erqing,Huang, You
, p. 3520 - 3527 (2014)
A novel strategy that involves phosphine-catalyzed sequential [2+3] and [3+2] annulation reactions was developed. In this domino reaction, γ-substituted allenoates were used as novel C4 synthons, and the bicyclic cyclopenta[b]dihydrofuran derivatives were produced in good to excellent diastereoselectivities and yields under mild conditions. Furthermore, preliminary studies on an asymmetric variant of this reaction proceeded with moderate enantioselectivity.
Stereo- and Regioselective [3+3] Annulation Reaction Catalyzed by Ytterbium: Synthesis of Bicyclic 1,4-Dihydropyridines
del Corte, Xabier,López-Francés, Adrián,de Marigorta, Edorta Martínez,Palacios, Francisco,Vicario, Javier
supporting information, p. 4761 - 4769 (2021/08/23)
An ytterbium catalyzed formal [3+3] cycloaddition of cyclic enamines and α,β-unsaturated ketones catalyzed is reported. The reaction proceeds with a ‘head to tail’ regioselectivity through a conjugate addition of the enamine moiety followed by an amine-carbonyl condensation. In addition the use of chiral enamines provided a high degree of stereoselectivity, driven by a possible balance between steric and π-stacking effects. The resulting bicyclic 1,4-dihydropyridines were evaluated as antiproliferative agents against A549 (carcinomic human alveolar basal epithelial cell) and SKOV3 (human ovarian carcinoma) human tumor cell lines. Good toxicities were found for some of the compounds against A549 and SKOV3 cell lines, with best IC50 values of 0.89 μM for A549 and 6.69 μM for SKOV3, and a very good selectivity was observed towards MRC5 (non-malignant) cell lines. (Figure presented.).
Facile synthesis of substituted diaryl sulfones: Via a [3 + 3] benzannulation strategy
Tang, Xiang-Zheng,Tong, Lang,Liang, Hua-Ju,Liang, Jie,Zou, Yong,Zhang, Xue-Jing,Yan, Ming,Chan, Albert S. C.
supporting information, p. 3560 - 3563 (2018/05/26)
A base-mediated [3 + 3] benzannulation strategy for the conversion of 1,3-bis(sulfonyl)propenes and β,γ-unsaturated α-ketoesters to diaryl sulfones has been developed. This method provides facile, metal-free and efficient access to highly substituted diaryl sulfones in good to excellent yields. In addition, the sulfonyl group could be easily removed or converted to other functional groups via an organostannane intermediate.
Boosting Chemical Stability, Catalytic Activity, and Enantioselectivity of Metal-Organic Frameworks for Batch and Flow Reactions
Chen, Xu,Jiang, Hong,Hou, Bang,Gong, Wei,Liu, Yan,Cui, Yong
, p. 13476 - 13482 (2017/10/05)
A key challenge in heterogeneous catalysis is the design and synthesis of heterogeneous catalysts featuring high catalytic activity, selectivity, and recyclability. Here we demonstrate that high-performance heterogeneous asymmetric catalysts can be engineered from a metal-organic framework (MOF) platform by using a ligand design strategy. Three porous chiral MOFs with the framework formula [Mn2L(H2O)2] are prepared from enantiopure phosphono-carboxylate ligands of 1,1′-biphenol that are functionalized with 3,5-bis(trifluoromethyl)-, bismethyl-, and bisfluoro-phenyl substituents at the 3,3′-position. For the first time, we show that not only chemical stability but also catalytic activity and stereoselectivity of the MOFs can be tuned by modifying the ligand structures. Particularly, the MOF incorporated with -CF3 groups on the pore walls exhibits enhanced tolerance to water, weak acid, and base compared with the MOFs with -F and -Me groups. Under both batch and flow reaction systems, the CF3-containing MOF demonstrated excellent reactivity, selectivity, and recyclability, affording high yields and enantioselectivities for alkylations of indoles and pyrrole with a range of ketoesters or nitroalkenes. In contrast, the corresponding homogeneous catalysts gave low enantioselectivity in catalyzing the tested reactions.
