Assembled Dendritic Titanium Catalysts for Enantioselective Hetero-Diels–Alder Reaction of Aldehydes with Danishefsky's Diene
作者:Baoming Ji、Yu Yuan、Kuiling Ding、Jiben Meng
DOI:10.1002/chem.200305286
日期:2003.12.15
titanium-catalyzed hetero-Diels-Alderreaction of Danishefsky's diene with aldehydes. These reactions afforded the corresponding 2-substituted 2,3-dihydro-4H-pyran-4-ones in quantitative yields and with excellent enantioselectivities (up to 97.2 % ee). The disposition of the dendritic wedges and the dendron size in the ligands were found to have significant impact on the enantioselectivity of the reaction. The recovered
One catalyst for two distinct reactions: sequential asymmetric hetero Diels–Alder reaction and diethylzinc addition
作者:Haifeng Du、Xue Zhang、Zheng Wang、Kuiling Ding
DOI:10.1016/j.tet.2005.08.007
日期:2005.10
addition to the benzaldehyde, affording the corresponding secondary alcohol with up to 94.5% ee under optimized conditions. On the basis of these facts, the integration of two distinct enantioselective reactions, HDA and diethylzincaddition reactions, has been realized in one-pot with the promotion of a single chiralzinc catalyst in a sequential manner. The impact of diimine additive on the catalytic system
1′-binaphthyl, and the structure was proved via X-ray analysis of its salicyl-aldehyde Schiff base, which was tested in the enantioselective titanium-catalyzed hetero-Diels-Alderreaction of Danishefsky’s diene with aldehydes. The reaction provided dihydropyranone in moderate to high yield (up to 99%) and enantioselectivities (up to 84.5% ee).
Enantiopure (P)- and (M)-3,14-bis(o-hydroxyaryl)tetrahydrobenzo[5]helicenediols and their helicene analogues: Synthesis, amplified circularly polarized luminescence and catalytic activity in asymmetric hetero-Diels–Alder reactions
作者:Lei Fang、Meng Li、Wei-Bin Lin、Chuan-Feng Chen
DOI:10.1016/j.tet.2018.10.047
日期:2018.12
exhibited more intense CPL with amplified glum, which might be attributed to the more rigid structure of PhOH-[5]HOLs. However, rigid PhOH-[5]HOLs was less effective in the catalytic asymmetrichetero-Diels–Alder (HAD) reactions than those of ArOH-H[5]HOLs with the flexible tetrahydro[5]helicene backbone that could adjust conformation to suit the substrates. Therefore, the helical chirality amplification
A Cr(salen)-based metal–organic framework as a versatile catalyst for efficient asymmetric transformations
作者:Qingchun Xia、Yan Liu、Zijian Li、Wei Gong、Yong Cui
DOI:10.1039/c6cc06019f
日期:——
A porous Cr(salen)-MOF can serve as an efficient and effective heterogeneous catalyst for a series of important asymmetric transformations including Nazarov cyclization, aminolysis reaction, Diels-Alder and hetero Diels-Alder reactions, resulting...