Work

Use of Group 4 Bis(sulfonamido) Complexes in the Intramolecular Hydroamination of Alkynes and Allenes

Year: 2003

Type: article

Abstract: 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.

Source: Journal of the American Chemical Society

DOI: 10.1021/ja0361547

Authors: Lutz Ackermann, Robert G. Bergman, Rebecca N. Loy

Institution: University of California, Berkeley

Language: English

Topic: Catalytic Alkyne Reactions

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: green

Funder: National Institute of General Medical Sciences

Awards: G4207910882, C-O AND C-N BOND FORMATION USING METAL BASED REAGENTS, C-O and C-N Bond Formation Using Metal-Based Reagents