Low‐Temperature Intramolecular [4+2] Cycloaddition of Allenes with Arenes for the Synthesis of Diene Ligands
作者:Durga Prasad Hari、Guillaume Pisella、Matthew D. Wodrich、Artem V. Tsymbal、Farzaneh Fadaei Tirani、Rosario Scopelliti、Jerome Waser
DOI:10.1002/anie.202012299
日期:2021.3
The intramolecular [4+2] cycloaddition between arenes and allenes first reported by Himbert gives rapid access to rigid polycyclic scaffolds. Herein, we report a one‐pot oxyalkynylation/cycloaddition reaction proceeding under mild conditions (23–90 °C) and providing complex polycyclic architectures with high efficiency, and atom and step economy. The bicyclo[2.2.2]octadiene products were obtained with
Enantioselective conjugate addition to cyclic enones with scalemic lithium organo(amido)cuprates, Part IV. Relationship between ligand structure and enantioselectivity
作者:Bryant E. Rossiter、Masakatsu Eguchi、Guobin Miao、Nicole M. Swingle、Amelia E. Hernández、Denise Vickers、Ezdan Fluckiger、R. Greg Patterson、K. Vásavi Reddy
DOI:10.1016/s0040-4020(01)86278-5
日期:1993.1
Scalemic lithium amides derived from primary and secondary amines react with organocopper compounds in ether or dimethyl sulfide to form lithium organo(amido)cuprates capable of enantioselective conjugate addition to 2-cycloalkenones. The most successful heterocuprate, in which the chiral ligand is (S)-N-methyl-1-phenyl-2-(1-piperidinyl)ethanamine, (S)-MAPP, 13, reacts with cyclic enones to form products
Design and Synthesis of Polymeric Chiral Bicyclo[3.3.0] Diene as Reusable Ligand for Rhodium-Catalyzed Asymmetric 1,4-Addition
作者:Hongyu Yang、Minghua Xu
DOI:10.1002/cjoc.201201079
日期:2013.1
A series of A‐B type sterically regular bicyclio[3.3.0] diene‐based polymers were designed and synthesized as immobilized chiraldieneligands for asymmetric catalysis. With polymericdiene 6b, good to excellent enantioselectivities can be achieved in Rh‐catalyzed asymmetric 1,4‐addition of arylboronic acids to α,β‐unsaturated ketones.
Unsymmetrical 1,1-diborated multisubstituted sp<sup>3</sup>-carbons formed via a metal-free concerted-asynchronous mechanism
作者:Ana B. Cuenca、Jessica Cid、Diego García-López、Jorge J. Carbó、Elena Fernández
DOI:10.1039/c5ob01523e
日期:——
unsymmetrical 1,1-diboration of diazo compounds, formed in situ from aldehydes and cyclic and non-cyclic ketones, in the absence of any transition metal complex. The heterolytic cleavage of the mixed diboron reagent, Bpin–Bdan, and the formation of two geminal C–Bpin and C–Bdan bonds has been rationalised based on DFT calculations to occur via a concerted-asynchronous mechanism. Diastereoselection is attained
Palladium-Catalyzed Asymmetric Conjugate Addition of Arylboronic Acids to Heterocyclic Acceptors
作者:Jeffrey C. Holder、Alexander N. Marziale、Michele Gatti、Bin Mao、Brian M. Stoltz
DOI:10.1002/chem.201203643
日期:2013.1.2
Flava Flavanone: Asymmetricconjugateadditions to chromones and 4‐quinolones are reported utilizing a single catalyst system formed in situ from Pd(OCOCF3)2 and (S)‐tBuPyOX. Notably, these reactions are performed in wet solvent under ambient atmosphere, and employ readily available arylboronicacids as the nucleophile, thus providing ready access to these asymmetric heterocycles (see scheme).