Given the importance of alkenylsilanes in organosilicon chemistry and material science, direct transition-metal-catalyzed selective hydrosilylation of alkynes with hydrosilanes has emerged as apowerful platform for ac...Given the importance of alkenylsilanes in organosilicon chemistry and material science, direct transition-metal-catalyzed selective hydrosilylation of alkynes with hydrosilanes has emerged as apowerful platform for accessing such building blocks in a straightforwardand atom-economical fashion [1,2]. Among them,regio- and stereoselective hydrosilylations of terminal alkynesand symmetrical internal alkynes have been thoroughly studied,and a range of 3d transition-metal catalysts exhibited excellentb-(E), b-(Z), and a-selectivity in these transformations [3–9].Despite these major advances, crucial drawbacks exist in thecatalytic hydrosilylation between hydrosilanes and unsymmetricalinternal alkynes, particularly when done in a regiodivergent andstereocontrolled fashion. The representative examples are largelyrestricted to the use of electronically [10] or sterically [11] biasedalkynes (Fig. 1a).展开更多
Simultaneously forming a carbon-carbon and a carbon-heteroatom bond in a single step through transition metal-catalyzed alkene difunctionalization strategy has emerged as a powerful tool for synthetic organic chemistr...Simultaneously forming a carbon-carbon and a carbon-heteroatom bond in a single step through transition metal-catalyzed alkene difunctionalization strategy has emerged as a powerful tool for synthetic organic chemistry.Due to the uncontrollable reactivity,direct cross-coupling with bromoallenes as the building blocks for the selective allenation and borylation remains challenging.We herein report a new type of S-and P-stabilized bromoallenes for palladium-catalyzed modular allenation and borylation of alkenes to the divergent synthesis of multiply functionalized allenes in a highly regio-and diastereoselective manifold.The reaction features broad substrate scope and wide functional group compatibility,thus providing a straightforward method to install allenyl and boryl groups across alkenes.Control experiments highlight the crucial importance of S-,P-stabilization for the oxidative insertion of Pd-species into the allenyl-Br bond.The facile syntheses of bioactive allenic steroids and exocyclic allenes demonstrate the synthetic utility of this protocol.展开更多
基金supported by the National Natural Science Foundation of China(22322108)Natural Science Foundation of Jiangsu Province(BK20231521 and BK20221355)Jiangsu Specially Appointed Professors Plan(SR10900122),and start-up funds from Soochow University.
文摘Given the importance of alkenylsilanes in organosilicon chemistry and material science, direct transition-metal-catalyzed selective hydrosilylation of alkynes with hydrosilanes has emerged as apowerful platform for accessing such building blocks in a straightforwardand atom-economical fashion [1,2]. Among them,regio- and stereoselective hydrosilylations of terminal alkynesand symmetrical internal alkynes have been thoroughly studied,and a range of 3d transition-metal catalysts exhibited excellentb-(E), b-(Z), and a-selectivity in these transformations [3–9].Despite these major advances, crucial drawbacks exist in thecatalytic hydrosilylation between hydrosilanes and unsymmetricalinternal alkynes, particularly when done in a regiodivergent andstereocontrolled fashion. The representative examples are largelyrestricted to the use of electronically [10] or sterically [11] biasedalkynes (Fig. 1a).
基金supported by the National Natural Science Foundation of China(22322108)Jiangsu Specially Appointed Professors Plan(SR10900122)the Natural Science Foundation of Jiangsu Province(BK20221355)。
文摘Simultaneously forming a carbon-carbon and a carbon-heteroatom bond in a single step through transition metal-catalyzed alkene difunctionalization strategy has emerged as a powerful tool for synthetic organic chemistry.Due to the uncontrollable reactivity,direct cross-coupling with bromoallenes as the building blocks for the selective allenation and borylation remains challenging.We herein report a new type of S-and P-stabilized bromoallenes for palladium-catalyzed modular allenation and borylation of alkenes to the divergent synthesis of multiply functionalized allenes in a highly regio-and diastereoselective manifold.The reaction features broad substrate scope and wide functional group compatibility,thus providing a straightforward method to install allenyl and boryl groups across alkenes.Control experiments highlight the crucial importance of S-,P-stabilization for the oxidative insertion of Pd-species into the allenyl-Br bond.The facile syntheses of bioactive allenic steroids and exocyclic allenes demonstrate the synthetic utility of this protocol.
