Rhodium‐Catalyzed Parallel Kinetic Resolution of Racemic Internal Allenes Towards Enantiopure Allylic 1,3‐Diketones
作者:Lukas J. Hilpert、Bernhard Breit
DOI:10.1002/anie.201903365
日期:2019.7.15
parallel kinetic resolution of racemic 1,3‐disubstituted allenes by means of a rhodium‐catalyzed addition to 1,3‐diketones furnishing enantiopure allylic 1,3‐diketones is described. Mechanistic experiments demonstrate that the different allene enantiomers react in parallel to either the diastereomeric E‐ or Z‐allylic 1,3‐diketones with the same absoluteconfiguration of the newly formed stereogenic
Regioselective Rhodium-Catalyzed Addition of 1,3-Dicarbonyl Compounds to Terminal Alkynes
作者:Thorsten M. Beck、Bernhard Breit
DOI:10.1021/acs.orglett.5b03391
日期:2016.1.4
A new method for the rhodium-catalyzed regioselective C–C bond formation using terminal alkynes and 1,3-dicarbonyl compounds to achieve valuable branched α-allylated 1,3-dicarbonyl products is reported. With a Rh(I)/DPEphos/p-CF3-benzoic acid as the catalyst system, the desired products can be obtained in good to excellent yields and with perfect regioselectivity. A broad range of functional groups
2,2-Difluoro-1,3-diketones as <i>gem</i>
-Difluoroenolate Precusors for Asymmetric Aldol Addition with <i>N</i>
-Benzylisatins
作者:Jinlong Qian、Wenbin Yi、Xin Huang、Jerry P. Jasinski、Wei Zhang
DOI:10.1002/adsc.201600392
日期:2016.9.1
2,2‐Difluoro‐1,3‐diketones are introduced as gem‐difluoroenolate precursors for the first example of an organocatalytic asymmetric aldol addition with N‐benzylisatins to form 3‐difluoroalkyl‐3‐hydroxyoxindoles.
Regio- and Enantioselective Rhodium-Catalyzed Addition of 1,3-Diketones to Allenes: Construction of Asymmetric Tertiary and Quaternary All Carbon Centers
作者:Thorsten M. Beck、Bernhard Breit
DOI:10.1002/anie.201610577
日期:2017.2.6
An unprecedented highly regio‐ and enantioselective rhodium‐catalyzed addition of 1,3‐diketones to terminal and 1,1‐disubstituted allenes furnishing asymmetric tertiary and quaternary all‐carboncenters is reported. By applying a RhI/phosphoramidite/TFA catalytic system under mild conditions, the desired chiral branched α‐allylated 1,3‐diketones could be obtained in good to excellent yields, with perfect
据报道,前所未有的高度区域和对映体选择性的铑催化向末端和1,1-二取代的丙二烯加成1,3-二酮,提供不对称的叔碳和季碳全中心。通过在温和的条件下应用Rh I /磷酰胺/ TFA催化体系,可以获得所需的手性支链α-烯丙基化的1,3-二酮,收率好至极好,具有良好的区域选择性和高对映选择性。该反应在两个反应伙伴上均显示出广泛的官能团耐受性,从而突出了其合成潜力。
Enantioselective Synthesis of 1,2-Dihydronaphthalenes via Oxidative N-Heterocyclic Carbene Catalysis
diastereo- and enantioselectiveN-heterocyclic carbene-catalyzed cascade annulation reactions using benzodiketones and enals under oxidative conditions, which afford a variety of 1,2-dihydronaphthalenes with two adjacent stereocenters in up to 99% yield, with >20:1 dr, and up to 99% ee, are reported. Furthermore, the product can be easily transformed to a series of useful compounds such as alcohol, amide,