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
report transition-metal-catalyzed B-H bond insertion reactions between borane adducts and alkynes to afford organoboron compounds in excellent yields under mild reaction conditions. This successful use of alkynes as carbene precursors in these reactions constitutes a new route to organoboron compounds. The startingmaterials are safe and readily available, and the reaction exhibits 100% atom-economy
Transition-Metal-Free Formal Decarboxylative Coupling of α-Oxocarboxylates with α-Bromoketones under Neutral Conditions: A Simple Access to 1,3-Diketones
作者:Zhen He、Xiaotian Qi、Shiqing Li、Yinsong Zhao、Ge Gao、Yu Lan、Yiwei Wu、Jingbo Lan、Jingsong You
DOI:10.1002/anie.201409361
日期:2015.1.12
A transition‐metal‐free formaldecarboxylativecoupling reaction between α‐oxocarboxylates and α‐bromoketones to synthesize 1,3‐diketone derivatives is presented. In this reaction, a broad scope of substrates can be employed, and neither a metal‐based reagent nor an additional base is required. DFT calculations reveal that this reaction proceeds through a coupling followed by decarboxylation mechanism
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.