Catalytic Dehydrogenative Stannylation of C(sp)–H Bonds Involving Cooperative Sn–H Bond Activation of Hydrostannanes
作者:Francis Forster、Victoria M. Rendón López、Martin Oestreich
DOI:10.1021/jacs.7b13088
日期:2018.1.31
a stannylium-ion-like tin electrophile by heterolytic cleavage of the Sn-H bond in hydrostannanes at the Ru-S bond of Ohki-Tatsumi complexes is reported. Reacting these activated hydrostannanes with terminal acetylenes does not lead to hydrostannylation of the C-C triple bond but to dehydrogenative stannylation of the alkyne terminus. The scope of this rare direct C(sp)-H bond stannylation with hydrostannanes
Molecular hydrogen adds to aliphatic and aromatic alkynylstannanes in the presence of a ruthenium catalyst, pushing the stannyl group to the adjacent carbon atom to give alpha-substituted vinylstannanes. This is the first achievement of hydrogenation of alkynylstannanes, which is applicable also to the deuteration affording precursors for an important class of deuterium-labeled compounds.
A Drastic Effect of TEMPO in Zinc‐Catalyzed Stannylation of Terminal Alkynes with Hydrostannanes via Dehydrogenation and Oxidative Dehydrogenation
With a system consisting of a catalytic zinc Lewis acid, pyridine, and TEMPO in a nitrile medium, terminalalkynes coupled with HSnBu3, providing alkynylstannanes with structural diversity. The resulting alkynylstannane, without being isolated, could be directly used for Pd‐ and Cu‐catalyzed transformations to deliver internal alkynes and more intricate tin‐atom‐containing molecules. Mechanistic studies
Selective Green Coupling of Alkynyltins and Allylic Halides to Trienynes via a Tandem Double Stille Reaction
作者:Isabel Meana、Ana C. Albéniz、Pablo Espinet
DOI:10.1002/adsc.201000430
日期:2010.11.22
The palladium-catalyzed reaction of alkynyltin compounds with allylic chlorides leads to a 2:2 coupling to give trienynes by regio- and stereoselective formation of three new CC bonds. The reaction can be applied to different alkynyl and allylic fragments, providing a wide range of trienynes with different substitution patterns in very good yields. They can be prepared in a green way using recyclable