Palladium-Catalyzed C−P Bond Formation: Mechanistic Studies on the Ligand Substitution and the Reductive Elimination. An Intramolecular Catalysis by the Acetate Group in PdIIComplexes

2008 ◽  
Vol 27 (22) ◽  
pp. 5876-5888 ◽  
Author(s):  
Marcin Kalek ◽  
Jacek Stawinski
Keyword(s):  
Bond Formation ◽  
Ligand Substitution ◽  
Reductive Elimination ◽  
Acetate Group ◽  
Mechanistic Studies ◽  
Intramolecular Catalysis ◽  
Palladium Catalyzed

scholarly journals Medium and Large N-Heterocycle Formation via Allene Hydroami-nation with a Bimetallic Rh(I) Catalyst

2021 ◽  
Author(s):  
Kelton Forson ◽  
Benjamin Bohman ◽  
Coriantumr Wayment ◽  
Rachel Owens ◽  
Caitlyn McKnight ◽  
...  
Keyword(s):  
Bimetallic Catalyst ◽  
Bond Formation ◽  
Product Formation ◽  
Reductive Elimination ◽  
High Yield ◽  
Mechanistic Studies ◽  
Bimetallic Complex ◽  
Bond Forming ◽  
Large N ◽  
The Difference

We report the synthesis of a bimetallic Rh(I) complex containing a bridging CO ligand that facilitates Rh–Rh bond formation. This bimetallic complex enables intramolecular allene hydroamination to form seven to ten-member rings in high yield. Monometallic Rh complexes, in contrast, fail to achieve any product formation. We demonstrate a broad substrate scope for formation of a variety of N-heterocycles in good to excellent yields. Macrocyclization reactions that form eleven to fifteen-membered heterocycles are also demonstrated. Mechanistic studies show that the reaction likely proceeds via catalyst protonation by trifluoroacetic acid, followed by reversible allene insertion and C–N bond-forming reductive elimination. The difference in product selectivity observed with our bimetallic catalyst vs monometallic Rh complexes may result from cooperativity between the two metals.

Palladium-catalyzed aerobic (1+2) annulation of Csp3–H bonds with olefin for the synthesis of 3-azabicyclo[3.1.0]hex-2-ene

2017 ◽  
Vol 53 (14) ◽  
pp. 2294-2297 ◽  
Author(s):  
Kun Wu ◽  
Lingkui Meng ◽  
Mingming Huai ◽  
Zhiliang Huang ◽  
Chao Liu ◽  
...  
Keyword(s):  
Reductive Elimination ◽  
Mechanistic Studies ◽  
Palladium Catalyzed

A novel Pd-catalyzed aerobic (1+2) annulation was developed and the palladation of Csp3–H bonds took place twice at the same position. Mechanistic studies by in situ IR revealed that the second C–H palladation and reductive elimination might be slow steps.

scholarly journals Medium and Large N-Heterocycle Formation via Allene Hydroamination with a Bimetallic Rh(I) Catalyst

2021 ◽  
Author(s):  
Kelton Forson ◽  
Benjamin Bohman ◽  
Coriantumr Wayment ◽  
Rachel Owens ◽  
Caitlyn McKnight ◽  
...  
Keyword(s):  
Bimetallic Catalyst ◽  
Bond Formation ◽  
Product Formation ◽  
Reductive Elimination ◽  
High Yield ◽  
Mechanistic Studies ◽  
Bimetallic Complex ◽  
Bond Forming ◽  
Large N ◽  
The Difference

We report the synthesis of a bimetallic Rh(I) complex containing a bridging CO ligand that facilitates Rh–Rh bond formation. This bimetallic complex enables intramolecular allene hydroamination to form seven to ten-member rings in high yield. Monometallic Rh complexes, in contrast, fail to achieve any product formation. We demonstrate a broad substrate scope for formation of a variety of N-heterocycles in good to excellent yields. Macrocyclization reactions that form eleven to fifteen-membered heterocycles are also demonstrated. Mechanistic studies show that the reaction likely proceeds via catalyst protonation by trifluoroacetic acid, followed by reversible allene insertion and C–N bond-forming reductive elimination. The difference in product selectivity observed with our bimetallic catalyst vs monometallic Rh complexes may result from cooperativity between the two metals.

Design and Development of Fe-Catalyzed Intra- and Intermolecular Carbofunctionalization of Vinyl Cyclopropanes

2019 ◽  
Author(s):  
Lei Liu ◽  
Wes Lee ◽  
Mingbin Yuan ◽  
Chris Acha ◽  
Michael B. Geherty ◽  
...  
Keyword(s):  
Bond Formation ◽  
Cross Coupling ◽  
Alkyl Halides ◽  
Grignard Reagents ◽  
Mechanistic Studies ◽  
Radical Intermediates ◽  
Design And Implementation ◽  
Solvent Cage ◽  
Radical Cascade ◽  
Radical Processes

Design and implementation of the first (asymmetric) Fe-catalyzed intra- and intermolecular difunctionalization of vinyl cyclopropanes (VCPs) with alkyl halides and aryl Grignard reagents has been realized via a mechanistically driven approach. Mechanistic studies support the diffusion of the alkyl radical intermediates out of the solvent cage to participate in an intra- or -intermolecular radical cascade with the VCP followed by re-entering the Fe radical cross-coupling cycle to undergo selective C(sp2)-C(sp3) bond formation. Overall, we provide new design principles for Fe-mediated radical processes and underscore the potential of using combined computations and experiments to accelerate the development of challenging transformations.

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