Enantioselective Construction of Cyclobutanes: A New and Concise Approach to the Total Synthesis of (+)-Piperarborenine B
作者:Jiang-Lin Hu、Liang-Wen Feng、Lijia Wang、Zuowei Xie、Yong Tang、Xiaoge Li
DOI:10.1021/jacs.6b08279
日期:2016.10.12
and multisubstituted alkenes was developed to furnish optically active cyclobutanes in high yields with >99/1 dr and up to >99% ee. By application of the newly developed method, the totalsynthesis of (+)-piperarborenine B was completed in eight steps from methylidenemalonate and olefin in 17% overall yield with >99/1 dr and 99% ee.
开发了一种高度非对映选择性和对映选择性 Cu(II)/SaBOX 催化的 [2+2] 环加成亚甲基丙二酸酯和多取代烯烃,以高产率提供光学活性环丁烷,产率 >99/1 dr 和高达 >99% ee。通过应用新开发的方法,从亚甲基丙二酸酯和烯烃分八步完成了 (+)-哌醋甲酯 B 的全合成,总产率为 17%,>99/1 dr 和 99% ee。
Selective Hydroarylation of 1,3-Diynes Using a Dimeric Manganese Catalyst: Modular Synthesis of <i>Z</i>
-Enynes
d selective hydroarylation of unsymmetrical alkynes represents the state‐of‐art in organic chemistry, and still mainly relies on the use of precious late‐transition‐metal catalysts. Reported herein is an unprecedented MnI‐catalyzed hydroarylation of unsymmetrical 1,3‐diyne alcohols with commercially available arylboronic acids with predictive selectivity. This method addresses the challenges in regio‐
Pyrrolidine‐Based P,O Ligands from Carbohydrates: Easily Accessible and Modular Ligands for the Ir‐Catalyzed Asymmetric Hydrogenation of Minimally Functionalized Olefins
作者:Pilar Elías‐Rodríguez、Carlota Borràs、Ana T. Carmona、Jorge Faiges、Inmaculada Robina、Oscar Pàmies、Montserrat Diéguez
DOI:10.1002/cctc.201801485
日期:2018.12.7
The potential of P,O‐iminosugar based ligands in the Ir‐catalyzed asymmetric hydrogenation of minimallyfunctionalizedolefins is presented. These new ligands were prepared from easily available carbohydrates (D‐mannose, D‐ribose and D‐arabinose). The stereochemical and polyfunctional diversity of carbohydrates allowed the modulation of the ligands, both from their electronic properties and the rigidity
Influence of the methyl group at C=C bridging bond of stilbene on the longest wavelength maximum in ultraviolet absorption spectra
作者:Yanxiu Zhang、Chao-Tun Cao、Jingyuan Zhang、Chenzhong Cao
DOI:10.1002/poc.3705
日期:2017.12
C(CH3)=CH, respectively, in which the C(CH3)=CH has a side‐group CH3 at the carbon‐carbon double bond. A series of XSMBY were synthesized, and their longest wavelength maximum λmax (nm) in ultravioletabsorptionspectra were measured in this work. We investigated the change regularity of the νmax (cm‐1, νmax = 1/λmax) of XSMBY and compared it with that of XSBY. The results indicate that (1) there is no
Chiral Bis(<i>N</i>-arylamino)phosphine-oxazolines: Synthesis and Application in Asymmetric Catalysis
作者:Marc Schönleber、Robert Hilgraf、Andreas Pfaltz
DOI:10.1002/adsc.200800221
日期:2008.9.5
N-alkylation of chiral 1,2-diamines followed by ring closure with phosphorus trichloride (PCl3) and subsequent coupling with an oxazoline alcohol resulted in a new class of N,Pligands. The corresponding iridium tetrakis[3,5-bis(trifluormethyl)phenyl]borate (BArF) complexes were found to be efficient catalysts for the enantioselectivehydrogenation of unfunctionalized olefins and α,β-unsaturated carboxylic