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Lutz Ackermann

Publications and source records attributed to Lutz Ackermann.

13 recordsLinked to original sources
PubMed2006

Air-stable PinP(O)H as preligand for palladium-catalyzed Kumada couplings of unactivated tosylates.

[reaction: see text] Air-stable and easily accessible PinP(O)H enables highly efficient palladium-catalyzed Kumada cross-coupling reactions of aryl tosylates. The in situ generated catalyst proved applicable not only to electron-rich and electron-poor carbocyclic tosylates but also to heterocyclic tosylates, such as pyridine and quinoline derivatives. The results described herein constitute the first use of air-stable secondary phosphine oxides as preligands for transition-metal-catalyzed coupling reactions between organometallic species and tosylates.

Journal Article↗
PubMed2005

Phosphine oxides as preligands in ruthenium-catalyzed arylations via C-H bond functionalization using aryl chlorides.

[reaction: see text] The use of air-stable, electron-rich phosphine oxides as preligands allows for unprecedented general ruthenium-catalyzed arylation reactions of pyridines and imines through C-H-bond activation using aryl chlorides. The catalytic system derived from a sterically hindered adamantyl-substituted phosphine oxide proves highly efficient and tolerates a number of important functional groups.

Journal Article↗
PubMed2005

General and efficient indole syntheses based on catalytic amination reactions.

[reaction: see text] Highly flexible and efficient syntheses of the indole backbone are presented starting from o-alkynylhaloarenes. These transformations proceed via a palladium- or a copper-catalyzed amination reaction and a subsequent cyclization reaction in good to excellent yields. Furthermore, a multicatalytic one-pot indole synthesis starting from o-chloroiodobenzene is viable using a single catalyst consisting of an N-heterocyclic carbene palladium complex and CuI.

Amination↗
PubMed2003

Use of group 4 bis(sulfonamido) complexes in the intramolecular hydroamination of alkynes and allenes.

Titanium tetrakis(amido) complexes catalyze the intramolecular hydroamination of alkynes and allenes more efficiently than Cp-based species. We report here that electron-withdrawing and sterically demanding bis(sulfonamido) ligands lead to enhanced catalytic activity. Zirconium analogues have also been prepared, and the tosyl-substituted complex 20 has been structurally characterized. As in the titanium series, bis(sulfonamido) zirconium catalysts are more efficient in the intramolecular hydroamination of allenes than bis(cyclopentadienyl) complex Cp(2)ZrMe(2) (23). Furthermore, these compounds transform 1,3-disubstituted aminoallenes with high stereoselectivity to the Z-allylamines and allow the hydroamination of a trisubstituted allene. Titanium bis(sulfonamido) imido complex 27 was synthesized. It converts aminoallene 10 to cylic imine 11 with a rate comparable to that of tetrakis(amide) 15, supporting the hypothesis of a catalytically active titanium imido intermediate.

Alkenes↗
PubMed2002

A highly reactive titanium precatalyst for intramolecular hydroamination reactions.

[reaction: see text]. Tetrakisamido titanium complexes are significantly more active than Cp2TiMe2 (1) in the intramolecular hydroamination of aminoalkynes and aminoallenes. In the latter case, the regioselectivity of the transformation depends on the nature of the precatalyst, yielding the most selective and reactive catalysis with the bis(sulfonamido) complex 11.

Amination↗