872595-10-3Relevant academic research and scientific papers
Enantioselective Reductive Coupling of Imines Templated by Chiral Diboron
Chen, Dongping,Li, Kaidi,Tang, Wenjun,Xu, Guangqing,Xu, Ronghua,Zhou, Mingkang
, p. 10337 - 10342 (2020/07/04)
We herein report a general, practical, and highly efficient method for asymmetric synthesis of a wide range of chiral vicinal diamines via reductive coupling of imines templated by chiral diboron. The protocol features high enantioselectivity and stereospecificity, mild reaction conditions, simple operating procedures, use of readily available starting materials, and a broad substrate scope. The method signifies the generality of diboron-enabled [3,3]-sigmatropic rearrangement.
Diboron glycol ester as well as preparation method, intermediate and application thereof
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Paragraph 0130-0135; 0156-0158, (2020/08/02)
The invention discloses diboron glycol ester as well as a preparation method, an intermediate and application thereof. The diboron glycol ester can be used for inducing reductive coupling reaction with imine as a substrate, and the substrate can be obtained by reaction of aldehyde and ammonia and is very easy to obtain and quite low in cost. The product can be separated from a reaction system onlyby acid-base operation without column chromatography purification, and the post-treatment mode is convenient and easy to operate. The yield of the obtained product is high, and protective group operation is not needed. The diboron glycol ester has chirality, the stereoselectivity of the reductive coupling reaction is generally excellent, and 99% ee chiral diamine can be obtained only through simple recrystallization. The diboron glycol ester can be obtained by reacting diol with diboron glycol ester, the diol is convenient to prepare and easy to amplify, the diol can be recycled from a reaction solution through simple acid-base operation, the recovery rate reaches 95%, and the preparation cost is further saved.
Synthesis and cytotoxic evaluation of novel platinum(II) complexes with C2-asymmetric and C2-symmetric chiral vicinal diamines
Zhang, Chen,Liu, Hongrui,Yang, Qing,Chang, Jun,Sun, Xun
, p. 154 - 158 (2013/08/24)
A series of new platinum(II) complexes with C2-asymmetric and C2-symmetric 1,2-diamines were designed and synthesized by convenient methods, involving samarium diiodide induced reductive coupling as the key step. The results of cytotoxicity showed that compounds (R,R)-11a and (S,S)-11a, two novel platinum(II) complexes with asymmetric 1,2-diamines, exhibited more potent cytotoxicity than that of oxaliplatin against all leukemia cell lines. Interestingly, (R,R)-11a and (S,S)-11a demonstrated less potent activity against three solid cancer cell lines than that of oxaliplatin, which indicated that these two compounds may only selectively inhibit the leukemia cell lines. In contrast, (R,R)-15a and (S,S)-15a, two platinum(II) complexes with symmetric 1,2-diamines, showed similar cytotoxicity to that of oxaliplatin against all leukemia cell lines and more potent activity against solid cancer cell lines. Further flow cytometry data indicated that (R,R)-11a could obviously arrest leukemia K562 cells in G2/M phases. A series of new platinum(II) complexes with C2-asymmetric and C2-symmetric 1,2-diamines were designed and synthesized by convenient methods, involving samarium diiodide induced reductive coupling as the key step. The cytotoxicity of these analogs against four leukemia and three solid cancer cell lines was evaluated and the preliminary structure-activity relationship is also discussed. Flow cytometry data indicated that (R,R)-11a could obviously arrest leukemia K562 cells in G2/M phases. Copyright
Highly diastereoselective and enantioselective addition of organometallic reagents to a chiral C2-symmetrical bisimine
Sun, Xiaoxia,Wang, Shuangjun,Sun, Shangjin,Zhu, Jin,Deng, Jingen
, p. 2776 - 2780 (2007/10/03)
An efficient and straightforward method has been developed for the preparation of enantiomerically enriched C2-symmetrical vicinal diamines via the addition of organometallic reagents to a chiral bisimine, which gives access to a variety of optically pure aromatic and aliphatic C 2-symmetrical vicinal diamines in high yields. The 'Cram-Davis' open transition state model is proposed to rationalize the observed stereoselectivities for the addition of organolithium reagents to the bisimine. Georg Thieme Verlag Stuttgart.
Electronic Control of Chiral Quaternary Center Creation in the Intramolecular Asymmetric Heck Reaction
Bucassa, Carl A.,Grossbach, Danja,Campbell, Scot J.,Dong, Yong,Eriksson, Magnus C.,Harris, Robert E.,Jones, Paul-James,Kim, Ji-Young,Lorenz, Jon C.,McKellop, Keith B.,O'Brien, Erin M.,et al.
, p. 5187 - 5195 (2007/10/03)
The Boehringer-Ingelheim phosphinoimidazoline (BIPI) ligands were applied to the formation of chiral quaternary centers in the asymmetric Heck reaction. Several different substrates were examined in detail using more than 70 members of this new ligand class. Hammett relationships were determined through systematic variation of the ligand electronics. All substrates showed essentially the same Hammett behavior, where enantioselectivity increased as the ligands were made more electron-deficient. Ligand optimization has led to catalysts which give the highest enantioselectivities reported to date for these difficult systems.
