The synthesis and efficient one-pot catalytic “self-breeding” of asymmetrical NC(sp<sup>3</sup>)E-hybridised pincer complexes
作者:Xiang-Yuan Yang、Wee Shan Tay、Yongxin Li、Sumod A. Pullarkat、Pak-Hing Leung
DOI:10.1039/c6cc00763e
日期:——
Cyclopalladation of the pyridyl-substituted chiral phosphine sulfide (N-P=S) and oxide (N-P=O) ligands afforded the asymmetric N-C(sp3)*-S and N-C(sp3)*-O pincer complexes. When applied as catalysts in asymmetric hydrophosphination, the newly developed...
Intramolecular CN Bond Formation under Metal-free Conditions: Synthesis of Indolizines
作者:Junliang Wu、Wei Lin Leng、Hongze Liao、Kim Le Mai Hoang、Xue-Wei Liu
DOI:10.1002/asia.201403400
日期:2015.4
Polysubstituted indolizine derivatives are constructed via intramolecularCNbondformation/CH bond cleavage under metal‐free conditions. These methods offer straightforward pathways to transform pyridyl chalcones into a variety of indolizines.
多取代的中氮茚衍生物经由分子内Ç构造 N键形成/ C 不含金属的条件下,H键裂解。这些方法提供了将吡啶基查耳酮转化为多种吲哚嗪的直接途径。
Phosphine-mediated enantioselective [1 + 4]-annulation of Morita–Baylis–Hillman carbonates with 2-enoylpyridines
作者:Tao Wang、Pengfei Zhang、Wenjun Li、Pengfei Li
DOI:10.1039/c8ra09453e
日期:——
This work describes a phosphine-catalyzedasymmetric [1 + 4] annulation of Morita–Baylis–Hillman carbonates with 2-enoylpyridines for constructing the enantiomerically enriched 2,3-dihydrofuran motif. In the presence of (−)-1,2-bis[(2R,5R)-2,5-dimethylphospholano]benzene, a series of Morita–Baylis–Hillman carbonates reacted with 2-enoylpyridines smoothly to afford a wide range of optically active 2
这项工作描述了膦催化的 Morita-Baylis-Hillman 碳酸盐与 2-烯酰基吡啶的不对称 [1 + 4] 环化,用于构建对映体富集的 2,3-二氢呋喃基序。在 (-)-1,2-bis[(2 R ,5 R )-2,5-dimethylphospholano]苯存在下,一系列 Morita-Baylis-Hillman 碳酸盐与 2-烯酰基吡啶顺利反应得到宽范围具有吡啶基序的光学活性 2,3-二氢呋喃的高产率和出色的不对称诱导。
Asymmetric 1,4-Conjugate Addition of Diarylphosphines to α,β,γ,δ-Unsaturated Ketones Catalyzed by Transition-Metal Pincer Complexes
作者:Xiang-Yuan Yang、Wee Shan Tay、Yongxin Li、Sumod A. Pullarkat、Pak-Hing Leung
DOI:10.1021/acs.organomet.5b00787
日期:2015.10.26
An enantioselective asymmetric 1,4-addition of diarylphosphines to linear alpha,beta,gamma,delta-unsaturated dienones was developed. A series of chiral PCP- and PCN-transition-metal (Pd, Pt and Ni) pincers, themselves prepared catalytically via asymmetric hydrophosphination, were sequentially screened to reveal the roles of backbone architecture and metal ion in catalyst design. The selected ester-functionalized PCP-palladium pincer afforded the chiral 1,4-phosphine adducts in excellent yields with up to >99% ee. The same catalyst when utilized for the hydrophosphination of an alpha,beta,gamma,delta-unsaturated malonate ester also revealed the critical role played by the ester functionality on the ligand backbone in dictating the enantioselectivity of the 1,6-adduct.
Design, Synthesis, and Evaluation of Chalcone Derivatives as Multifunctional Agents against Alzheimer's Disease
Fifteen chalcone derivatives 3a–3o were synthesized, and evaluated as multifunctionalagentsagainst Alzheimer's disease. In vitro studies revealed that these compounds inhibited self-induced Aβ1-42 aggregation effectively ranged from 45.9–94.5 % at 20 μM, and acted as potential antioxidants. Their structure-activity relationships were summarized. In particular, (2E)-3-[4-(dimethylamino)phenyl]-1-