Polyene Cyclization Promoted by the Cross Conjugated α-Carbalkoxy Enone System. An Efficient Approach to Highly Functionalized Decalins
摘要:
AbstractThe cross conjugated α‐carbalkoxy enone system was found to be an excellent promoter for polyene cyclization. Under mild conditions, the reaction occurred readily with a high degree of regio‐ and stereoselectivity. Based on this facile process, an efficient method for the construction of highly functionalized decalin derivatives has been developed.
Allyl-Nickel Catalysis Enables Carbonyl Dehydrogenation and Oxidative Cycloalkenylation of Ketones
作者:David Huang、Suzanne M. Szewczyk、Pengpeng Zhang、Timothy R. Newhouse
DOI:10.1021/jacs.9b02552
日期:2019.4.10
of carbonyl compounds using allyl-nickel catalysis. This development overcomes several limitations of previously reported allyl-palladium-catalyzed oxidation, and is further leveraged for the development of an oxidative cycloalkenylation reaction that provides access to bicycloalkenones with fused, bridged, and spirocyclic ring systems using unactivated ketone and alkene precursors.
Zinc-mediated anionic cyclization of unstabilized ketone enolates with unactivated alkenes
作者:Diego Olivieri、David Huang、Alexandra K. Bodnar、Shijin Yu、Timothy R. Newhouse
DOI:10.1016/j.tet.2020.131417
日期:2020.12
We report herein general conditions for a zinc-mediated anionic cyclization of unstabilized ketoneenolates. This anionic cyclization allows access to various carbocyclic architectures by utilizing abundant ketones and unactivated alkenes as precursors. The transformation is enabled by the use of Zn(TMP)2 as base and Zn(OTf)2 as an additive. The resulting alkylzinc species can be intercepted by electrophiles
Nickel-Catalyzed Difunctionalization of Unactivated Alkenes Initiated by Unstabilized Enolates
作者:David Huang、Diego Olivieri、Yang Sun、Pengpeng Zhang、Timothy R. Newhouse
DOI:10.1021/jacs.9b09245
日期:2019.10.16
This report demonstrates the possibility of a nickel-catalyzed difunctionalization of unactivated alkenes initiated by an unstabilized enolate nucleophile. The process tolerates a diverse range of electrophiles, including aryl, heteroaryl, alkenyl, and amino electrophiles. An electron-deficient phosphine ligand and a tetrabutylammonium salt additive were crucial for promoting efficient vicinal difunctionalization.
Reductive cyclization of mercurial enones
作者:Samuel Danishefsky、Samuel Chackalamannil、Biing Jiun Uang