Bifunctional Polyene Cyclizations: Synthetic Studies on Pimarane Natural Products
作者:Julian M. Feilner、Immanuel Plangger、Klaus Wurst、Thomas Magauer
DOI:10.1002/chem.202101926
日期:2021.8.25
Polyenecyclizations generate molecular complexity from a linear polyene in a single step. While methods to initiate these cyclizations have been continuously expanded and improved over the years, the majority of polyene substrates are still limited to simple alkyl-substituted alkenes. In this study, we took advantage of the unique reactivity of higher-functionalized bifunctional alkenes. The realization
作者:Kay M. Brummond、Peter C. Sill、Brenden Rickards、Steven J. Geib
DOI:10.1016/s0040-4039(02)00633-0
日期:2002.5
This manuscript describes a silicon-tethered Pauson–Khandreaction and subsequent cleavage of the resulting vinyl silane to afford functionalized alkylidene cyclopentenones. Altering the reaction conditions affords a selective reaction with either π-bond of the allene.
Rhodium‐Catalyzed Asymmetric Intramolecular Hydroamination of Allenes
作者:Dino Berthold、Arne G. A. Geissler、Sabrina Giofré、Bernhard Breit
DOI:10.1002/anie.201904833
日期:2019.7.15
The rhodium‐catalyzed asymmetric intramolecular hydroamination of sulfonyl amides with terminal allenes is reported. It provides selective access to 5‐ and 6‐membered N‐heterocycles, scaffolds found in a large range of different bioactive compounds. Moreover, gram scale reactions, as well as the application of suitable product transformations to natural products and key intermediates thereof are demonstrated
Construction of enantioenriched polysubstituted hexahydropyridazines via a sequential multicatalytic process merging palladium catalysis and aminocatalysis
The powerful combination of organic and metal catalysis in a single vessel allowed the formation of enantioenriched polysubstituted cyclic 6-membered hydrazines bearing a quaternary stereocenter in good yields and selectivities.
Nickel(0)‐Catalyzed Hydrocyanation of Terminal Allenes: A Regio‐ and Enantioselective Approach to Branched Allylic Nitriles
作者:Timm Bury、Sven Kullmann、Bernhard Breit
DOI:10.1002/adsc.202201189
日期:2023.2.7
A highly branched regioselective nickel(0)-catalyzed hydrocyanation of mono- and 1,1-disubstituted allenes as well as an asymmetric hydrocyanation of 1,1-disubstituted allenes are reported herein, giving access to branched tertiary and quaternary β,γ-allylic nitriles. For the regioselective hydrocyanation of terminal allenes, a nickel(0)/Biphephos catalytic system applicable to a substrate scope containing