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Your search keyword '"Florian F. Kneisel"' showing total 9 results
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9 results on '"Florian F. Kneisel"'

1. Preparation and Reactions of Highly Functionalized Bis-Arylzinc Reagents Using a Li(acac)-Catalyzed Iodine-Zinc Exchange

Author

Florian F. Kneisel, Helena Leuser, and Paul Knochel

Subjects
chemistry, Reagent, Organic Chemistry, chemistry.chemical_element, Organic chemistry, Lithium, Zinc, Iodine, Catalysis
Abstract

Polyfunctional bis-arylzinc reagents are accessible via a new lithium acetylacetonate-catalyzed iodine-zinc exchange. This protocol tolerates sensitive functional groups (ketones, aldehydes or isothiocyanates) in the aryliodides and allows the formation of highly functionalized zinc reagents. These zinc reagents can be used in a variety of catalyzed and uncatalyzed transformations.

Published
2005

2. Highly Functionalized Organomagnesium Reagents Prepared through Halogen-Metal Exchange

Author

Nina Gommermann, Florian F. Kneisel, Paul Knochel, Felix Kopp, Viet Anh Vu, Wolfgang Dohle, Ioannis Sapountzis, and Tobias J. Korn

Subjects
Magnesium, Grignard reaction, chemistry.chemical_element, General Chemistry, Catalysis, chemistry.chemical_compound, chemistry, Reagent, Halogen, Nitro, Organic chemistry, Amination, Organometallic chemistry, Group 2 organometallic chemistry
Abstract

Organomagnesium reagents occupy a central position in synthetic organic and organometallic chemistry. Recently, the halogen-magnesium exchange has considerably extended the range of functionalized Grignard reagents available for synthetic purposes. Functional groups such as esters, nitriles, iodides, imines, or even nitro groups can be present in a wide range of aromatic and heterocyclic organomagnesium reagents. Also various highly functionalized alkenyl magnesium species can be prepared. These recent developments as well as new applications of organomagnesium reagents in cross-coupling reactions and amination reactions will be covered in this Review.

Published
2003

3. Highly Stereoselective Anti SN2‘ Substitutions of (Z)-Allylic Pentafluorobenzoates with Polyfunctionalized Zinc−Copper Reagents

Author

Helena Leuser, Paul Knochel, Florian F. Kneisel, Harrington-Frost N, and Calaza Mi

Subjects
Substitution reaction, Allylic rearrangement, Stereochemistry, Organic Chemistry, chemistry.chemical_element, Regioselectivity, Zinc, Biochemistry, chemistry, Reagent, SN2 reaction, Stereoselectivity, Physical and Theoretical Chemistry, Selectivity
Abstract

[reaction: see text] Allylic substitution reactions of zinc-copper organometallics on (Z)-allylic pentafluorobenzoates proceed with very high regioselectivity and excellent anti selectivity. The high fidelity in transfer of stereochemical information allowed a short synthesis of (+)-ibuprofen (97% ee).

Published
2003

4. Stereoselective cyclizations mediated by functionalized organomagnesium reagents and catalyzed by cobalt or copper salts

Author

Kolja M. Knapp, Florian F. Kneisel, Paul Knochel, Yasunari Monguchi, and Hendrik Zipse

Subjects
Chemistry, Organic Chemistry, Leaving group, chemistry.chemical_element, Ring (chemistry), Biochemistry, Copper, Catalysis, Reagent, Drug Discovery, Polymer chemistry, Organic chemistry, Molecule, Stereoselectivity, Cobalt
Abstract

The iodine–magnesium exchange reaction with i -PrMgCl allows a mild preparation of functionalized arylmagnesium compounds bearing a leaving group in the molecule. With the appropriate transition-metal catalyst (a copper or cobalt salt), cyclization reactions occur leading to five- or six-membered ring systems in good yields.

Published
2002

5. Synthesis and Reactivity of Aryl- and Heteroaryl-Magnesium Reagents Bearing Keto Groups

Author

Florian F. Kneisel and Paul Knochel

Subjects
chemistry.chemical_classification, Ketone, Magnesium, Aryl, Organic Chemistry, chemistry.chemical_element, General Medicine, Medicinal chemistry, chemistry.chemical_compound, chemistry, Bromide, Reagent, Electrophile, Organic chemistry, Reactivity (chemistry)
Abstract

The reaction of iodophenyl ketones with neo-pentylmagnesium bromide in THF or THF:NMP or THF:DMAC mixtures allows the first preparation of aryl- and heteroarylmagnesium species bearing a ketone. Under appropriate conditions, these new reagents react with a range of electrophiles, leading to polyfunctional products.

Published
2002

6. ChemInform Abstract: Stereoselective Cyclizations Mediated by Functionalized Organomagnesium Reagents and Catalyzed by Cobalt or Copper Salts

Author

Yasunari Monguchi, Hendrik Zipse, Kolja M. Knapp, Paul Knochel, and Florian F. Kneisel

Subjects
chemistry, Reagent, Polymer chemistry, Leaving group, chemistry.chemical_element, Molecule, Stereoselectivity, General Medicine, Ring (chemistry), Cobalt, Copper, Catalysis
Abstract

The iodine–magnesium exchange reaction with i -PrMgCl allows a mild preparation of functionalized arylmagnesium compounds bearing a leaving group in the molecule. With the appropriate transition-metal catalyst (a copper or cobalt salt), cyclization reactions occur leading to five- or six-membered ring systems in good yields.

Published
2010

7. Functionalized Organozinc Compounds

Author

Helena Leuser, Paul Knochel, Liu‐Zhu Gong, Florian F. Kneisel, and Sylvie Perrone

Subjects
Chemistry, Negishi coupling, Reagent, Zinc metal, chemistry.chemical_element, Halide, Organic chemistry, Lithium, Oxidative addition
Abstract

1 Introduction 2 Methods of Preparation of Polyfunctional Organozinc Reagents 3 Reactions of Organozinc Reagents 4 Conclusion Keywords: functionalized organozinc compounds; polyfunctional organozinc reagents; polyfunctional organozinc halides; oxidative addition to zinc metal; diorganozinc preparation; boron–zinc exchange; lithium triorganozincates; organozinc reagent reaction

Published
2009

8. ChemInform Abstract: Functionalized Organozinc Compounds

Author

Helena Leuser, Paul Knochel, Sylvie Perrone, Florian F. Kneisel, and Liu‐Zhu Gong

Subjects
chemistry, Reagent, Zinc metal, chemistry.chemical_element, Halide, Lithium, General Medicine, Combinatorial chemistry, Oxidative addition
Abstract

1 Introduction 2 Methods of Preparation of Polyfunctional Organozinc Reagents 3 Reactions of Organozinc Reagents 4 Conclusion Keywords: functionalized organozinc compounds; polyfunctional organozinc reagents; polyfunctional organozinc halides; oxidative addition to zinc metal; diorganozinc preparation; boron–zinc exchange; lithium triorganozincates; organozinc reagent reaction

Published
2009

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