Cobalt-Catalyzed Enantioselective Hydroarylation of 1,6-Enynes
摘要:
An asymmetric hydroarylative cyclization of enynes involving a C-H bond cleavage is reported. The cobalt-catalyzed cascade generates three new bonds in an atom-economical fashion. The products were obtained in excellent yields and excellent enantioselectivities as single diastereo- and regioisomers. Preliminary mechanistic studies indicate that the reaction shows no intermolecular C-H crossover. This work highlights the potential of cobalt catalysis in C-H bond functionalization and enantioselective domino reactivity.
cobalt‐catalyzed hydroacylation of 1,6‐enynes with exogenous aldehydes in a domino sequence to construct enantioenriched ketones. The products were obtained in good yields with excellent regio‐, diastereo‐, and enantioselectivity. Furthermore, the chiral products served as valuable precursors to access complex spirocyclic scaffolds with three contiguous stereocenters. The asymmetric hydroacylation process exhibited
Asymmetric Cobalt‐Catalyzed Regioselective Hydrosilylation/Cyclization of 1,6‐Enynes
作者:Yang'en You、Shaozhong Ge
DOI:10.1002/anie.202100775
日期:2021.5.17
>99 % ee. This cobalt‐catalyzed hydrosilylation/cyclization also occurred with prochiral secondary hydrosilane PhMeSiH2 to yield chiral alkylsilanes containing both carbon‐ and silicon‐stereogenic centers with excellent enantioselectivity, albeit with modest diastereoselectivity. The chiral organosilane products from this cobalt‐catalyzed asymmetrichydrosilylation/cyclization could be converted to
Cobalt-Catalyzed Enantioselective Hydroarylation of 1,6-Enynes
作者:Andrew Whyte、Alexa Torelli、Bijan Mirabi、Liher Prieto、José F. Rodríguez、Mark Lautens
DOI:10.1021/jacs.0c03246
日期:2020.5.20
An asymmetric hydroarylative cyclization of enynes involving a C-H bond cleavage is reported. The cobalt-catalyzed cascade generates three new bonds in an atom-economical fashion. The products were obtained in excellent yields and excellent enantioselectivities as single diastereo- and regioisomers. Preliminary mechanistic studies indicate that the reaction shows no intermolecular C-H crossover. This work highlights the potential of cobalt catalysis in C-H bond functionalization and enantioselective domino reactivity.
Rhodium-Catalyzed Asymmetric [2+2+2] Cyclization of 1,6-Enynes and Aldehydes
Asymmetric catalysis: The rhodium‐catalyzed asymmetric [2+2+2] cyclization of 1,6‐enynes and aldehydes was achieved by using a cationicrhodium(I)/(R)‐binapcomplex as a catalyst (see scheme; cod=1,5‐cyclooctadiene). Coordination of the substrate heteroatom to the cationicrhodium plays an important role in this cyclization reaction.