Stereoselective Synthesis of (E)-4-Alkylidenecyclopent-2-en-1-ones by a Tandem Ring Closure−Michael Addition−Elimination
摘要:
[GRAPHICS]Reaction of (Z)-1,4-diketones with various functionalized nitroalkanes in the presence of DBU gives 4-alkylidenecyclopent-2-en-1-ones with E selectivity, A cyclopentadienone intermediate is probably formed by intramolecular aldol condensation, and this reacts with a nitroalkane giving a Michael addition-elimination.
Rhodium-Catalyzed Intermolecular Carbonylative [2 + 2 + 1] Cycloaddition of Alkynes Using Alcohol as the Carbon Monoxide Source for the Formation of Cyclopentenones
作者:Ju Hyun Kim、Taemoon Song、Young Keun Chung
DOI:10.1021/acs.orglett.7b00458
日期:2017.3.3
regioselective rhodium-catalyzed intermolecular carbonylative [2 + 2 + 1] cycloaddition of alkynes using alcohol as a CO surrogate to access 4-methylene-2-cyclopenten-1-ones has been developed. In this transformation, the alcohol performs multiple roles, including generating the Rh–H intermediate, functioning as the CO source, and assisting in the isomerization of the alkyne. Alkynes can act as both the olefin
Study of the reactions of substituted allenes with tris(triphenylphosphine)nickel(0). An analysis of the factors affecting the regio- and stereochemistry of .pi.-complex formation and coupling to form nickelacyclopentane complexes
作者:Daniel J. Pasto、Naizhong Huang、Charles W. Eigenbrot