A highly diastereoselective addition of substituted racemic allylic zinc reagents to chiral N- tert-butanesulfinylimines resulting in the formation of homoallylic amines is reported. This method is quite general and also efficient for the preparation of enantiomerically pure homoallylic amines bearing quaternary centers and also adjacent quaternary centers.
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http://dx.doi.org/10.1021/ol800998u | DOI Listing |
Acc Chem Res
January 2025
Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, United States.
ConspectusThe manipulation of strained rings is a powerful strategy for accessing the valuable chemical frameworks present in natural products and active pharmaceutical ingredients. Aziridines, the smallest N-containing heterocycles, have long served as building blocks for constructing more complex amine-containing scaffolds. Traditionally, the reactivity of typical aziridines has been focused on ring-opening by nucleophiles or the formation of 1,3-dipoles.
View Article and Find Full Text PDFOrg Biomol Chem
January 2025
Univ Rennes, CNRS, ISCR - UMR 6226, F-35000 Rennes, France.
A straightforward and highly diastereoselective synthesis of -4-hydroxypiperidines is presented. This method allows access to C2 and C4 substituted piperidines, bearing a tetrasubstituted carbon stereocenter at C4. -Disubstituted homoallylic amines and ketoaldehydes as carbonyl partners have been rarely used in aza-Prins cyclizations, expanding the scope of this reaction.
View Article and Find Full Text PDFJ Org Chem
January 2025
Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo 060-0812, Japan.
Using amines in catalytic transfer hydrogenation (TH) is challenging, despite their potential availability as a hydrogen source. Here, we describe a photoredox/nickel-catalyzed TH of alkyne through an intermediary aminoalkyl Ni species. This reaction successfully provided functionalized ()-alkenes, such as (homo)allyl ethers, alcohols, and amides (/ = up to >99:1), and the reaction thus bypasses a limitation of substrate scope in TH using amine and a Lindlar catalyst.
View Article and Find Full Text PDFBeilstein J Org Chem
September 2024
Department of Chemistry, Loughborough University, Loughborough, LE11 3TU, UK.
In recent decades, the chiral allylation of imines emerged as a key methodology in the synthesis of alkaloids and natural products with 4-, 5- and 6-membered cyclic amine motifs. Initially reliant on stoichiometric reagents, synthetic chemists predominantly used -substituted chiral imines, organometallic chiral reagents and achiral reagents with an equimolar chiral controller. However, recent years have witnessed the rise of asymmetric transition-metal catalysts and, importantly, organocatalytic allylation, reshaping the landscape of modern synthetic chemistry.
View Article and Find Full Text PDFThe unexpected 4,1-hydroaminoalkylation of dienes provides selective access to linear homoallylic amines by zirconium catalysis. This switch from the traditional branched preferred regioselectivity to selective linear product formation using this early transition metal can be attributed to π-allyl intermediates. The reactivity of these isolated intermediates on a sterically accessible and coordinatively flexible chelating bis(ureate) Zr(iv) complex confirmed reversible C-C bond formation in hydroaminoalkylation catalysis.
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