Development of (Trimethylsilyl)ethyl Ester Protected Enolates and Applications in Palladium-Catalyzed Enantioselective Allylic Alkylation: Intermolecular Cross-Coupling of Functionalized Electrophiles
作者:Corey M. Reeves、Douglas C. Behenna、Brian M. Stoltz
DOI:10.1021/ol500355z
日期:2014.5.2
compounds in palladium-catalyzedasymmetricallylicalkylation is explored, yielding a variety of α-quaternary six- and seven-membered ketones and lactams. Independent coupling partner synthesis engenders enhanced allyl substrate scope relative to traditional β-ketoester substrates; highly functionalized α-quaternary ketones generated by the union of (trimethylsilyl)ethyl β-ketoesters and sensitive
Formation of allylated quaternary carbon centers <i>via</i> C–O/C–O bond fragmentation of oxalates and allyl carbonates
作者:Haifeng Chen、Yang Ye、Weiqi Tong、Jianhui Fang、Hegui Gong
DOI:10.1039/c9cc07072a
日期:——
emphasizes Fe-promoted cross-electrophile allylation of tertiaryalkyl oxalates with allyl carbonates that generates all C(sp3)-quaternary centers. The reaction involves fragmentation of tertiaryalkyl oxalate C-O bonds to give tertiaryalkyl radical intermediates, addition of the radicals to less hindered alkene terminals, and subsequent cleavage of the allyl C-O bonds. Allylation with 2-aryl substituted
Aminative Umpolung of Aldehydes to α-Amino Anion Equivalents for Pd-Catalyzed Allylation: An Efficient Synthesis of Homoallylic Amines
作者:Lei Ding、Jing Chen、Yifan Hu、Juan Xu、Xing Gong、Dongfang Xu、Baoguo Zhao、Hexing Li
DOI:10.1021/ol4034012
日期:2014.2.7
An attractive strategy for generation of α-aminoanionsfrom aldehydes with applications in synthesis of homoallylic amines is described. Aromatic aldehydes can be converted to α-aminoanionequivalents via amination with 2,2-diphenylglycine and subsequent decarboxylation. The in situ generated α-imino anions are highly reactive for Pd-catalyzed allylation, forming the corresponding homoallylic amines
The Enantioselective Intermolecular Saegusa Allylation
作者:Ji Liu、Edward M. Laguna、Arun Raj Kizhakkayil Mangadan、Kyoungmin Kang、Aaron Aponick
DOI:10.1021/acscatal.1c04546
日期:2021.12.17
A simple procedure for the intermolecular enantioselective palladium-catalyzeddecarboxylativeallylation of β-ketoacids is described. This method, inspired by a stoichiometric control experiment performed by Saegusa and co-workers some 40+ years ago, makes use of allyl carbonates as the coupling substrates and enables direct access to α-allylated ketones bearing newly formed quaternary stereocenters