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Nicolai Cramer

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Publications associées (117)

Ketene Aminal Phosphates: Competent Substrates for Enantioselective Pd(0)-Catalyzed C-H Functionalizations

Nicolai Cramer, Daria Grosheva

Enantioselective Pd(0)-catalyzed C-H functionalizations of ketene aminal phosphates provide isoindoline scaffolds with high enantioselectivity at ambient temperature. The high level of enantiocontrol is enabled by a tailored monodentate electron-rich phosp ...

2017

Cooperative Effects between Chiral Cp-x-Iridium(III) Catalysts and Chiral Carboxylic Acids in Enantioselective C-H Amidations of Phosphine Oxides

Nicolai Cramer, Michael Christian Dieckmann, Yun-Suk Jang

An enantioselective C-H amidation of phosphine oxides by using an iridium(III) catalyst bearing an atropchiral cyclopentadienyl (Cp-x) ligand is reported. A very strong cooperative effect between the chiral Cp-x ligand and a phthaloyl tert-leucine enabled ...

Wiley-Blackwell2017

A β-Carbon elimination strategy for convenient in situ access to cyclopentadienyl metal complexes

Anne-Clémence Corminboeuf, Matthew Wodrich, Nicolai Cramer, Gints Smits, Benoît Daniel Bertrand Audic

The electronic and steric properties of tailored cyclopentadienyl (Cp) ligands are powerful handles to modulate the catalytic properties of their metal complexes. This requires the individual preparation, purification and storage of each ligand/metal combi ...

2017

Chiral Cyclopentadienyl Ruthenium Complexes as Versatile Catalysts for Enantioselective Transformations

Nicolai Cramer, David Kossler

Ruthenium complexes, in particular cyclopentadienyl ruthenium (II) derivatives, catalyze a vast number of transformations in the field of homogenous catalysis. Herein we describe the first synthesis of efficient chiral cationic cyclopentadienyl ruthenium ( ...

Schweizerische Chemische Gesellschaft2017

Catalytic Enantioselective Transformations Involving C-H Bond Cleavage by Transition-Metal Complexes

Nicolai Cramer, Christopher Gordon Newton, Shouguo Wang, Caio Costa Oliveira

The development of new methods for the direct functionalization of unactivated C-H bonds is ushering in a paradigm shift in the field of retrosynthetic analysis. In particular, the catalytic enantioselective functionalization of C-H bonds represents a high ...

2017

Divergent Asymmetric Synthesis of Polycyclic Compounds via Vinyl Triazenes

Kay Severin, Rosario Scopelliti, Gregor Kiefer, Florian Gérald Abela, Nicolai Cramer, David Kossler, Abdusalom Suleymanov

Vinyl triazenes were obtained by enantioselective [2+2] cycloaddition reactions of bicyclic alkenes with 1-alkynyl triazenes in the presence of a RuII catalyst with a chiral cyclopentadienyl ligand. These triazenes serve as unique vinyl cation surrogates. ...

Wiley-VCH Verlag GmbH2017

One-Step Multigram-Scale Biomimetic Synthesis of Psiguadial B

Matthew Wodrich, Nicolai Cramer, Duc Tran Ngoc, Christopher Gordon Newton

A gram-scale synthesis of psiguadial B, a purported inhibitor of human hepatoma cell growth, has been achieved in one step by a biomimetic three-component coupling of caryophyllene, benzaldehyde, and diformylphloroglucinol. This cascade reaction is catalyz ...

Wiley-VCH Verlag GmbH2017

Neutral chiral cyclopentadienyl Ru(II)Cl catalysts enable enantioselective [2+2]-cycloadditions

Nicolai Cramer, David Kossler

Cyclopentadienyl ruthenium(II) complexes with a large number of available coordination sites are frequently used catalysts for a broad range of transformations. To be able to render these transformations enantioselective, we have designed a chiral neutral ...

2017

Enantioselective C-H Functionalization-Addition Sequence Delivers Densely Substituted 3-Azabicyclo[3.1.0]hexanes

Nicolai Cramer, Julia Pedroni

An enantioselective C-H functioffalization route to perfluoroalkyl-containing 3-azabicyclo[3.1.0]-hexanes is disclosed. A modular and bench-stable diazaphospholane ligand enables highly enantioselective Pd(0)-catalyzed cyclopropane C-H functionalization us ...

American Chemical Society2017

Designer Anhydride Clears the Path for Alkoxycarbonylations in Catellani Reactions

Nicolai Cramer

In this issue of Chem, Dong and colleagues show that an engineered mixed carboxylate carbonate anhydride serves as an electrophilic trap in palladium/norbornene-catalyzed double functionalization of aryl iodides, enabling the introduction of the synthetica ...

Cell Press2016

Asymmetric Catalysis Powered by Chiral Cyclopentadienyl Ligands

Nicolai Cramer, David Kossler, Christopher Gordon Newton

Application of chiral derivatives of the versatile and ubiquitous cyclopentadienyl ligand has long remained an underdeveloped area in asymmetric catalysis. In this Perspective we highlight recent exciting results that demonstrate their enormous potential. ...

American Chemical Society2016

Converting disulfide bridges in native peptides to stable methylene thioacetals

Nicolai Cramer, Christopher Matthew Bandeli Kourra

Disulfide bridges play a crucial role in defining and rigidifying the three-dimensional structure of peptides. However, disulfides are inherently unstable in reducing environments. Consequently, the development of strategies aiming to circumvent these defi ...

Royal Soc Chemistry2016

2-(Trifluoromethyl)indoles via Pd(0)-Catalyzed C(sp(3))-H Functionalization of Trifluoroacetimidoyl Chlorides

Nicolai Cramer, Julia Pedroni

Perfluoroalkylated indoles are valuable compounds in drug discovery. A Pd(0)-catalyzed C(sp(3))-H functionalization enables access to 2-(trifluoromethyl)indoles from trifluoroacetimidoyl chlorides. These are stable compounds, easily obtained from anilines. ...

American Chemical Society2016

Enantioselective Access to Spirocyclic Sultams by Chiral Cp-x-Rhodium(III)-Catalyzed Annulations

Nicolai Cramer, Van Manh Pham

Chiral spirocyclic sultams are a valuable compound class in organic and medicinal chemistry. A rapid entry to this structural motif involves a [3+2] annulation of an N-sulfonyl ketimine and an alkyne. Although the directing-group properties of the imino gr ...

Wiley-Blackwell2016

Total Synthesis of Fijiolide A

Nicolai Cramer, Christoph Heinz

Fijiolide A is a secondary metabolite isolated from a marine-derived actinomycete of the genus Nocardiopsis. It was found to significantly reduce the TNF-alpha induced activity of the transcription factor NF kappa B, which is considered a promising target ...

Schweizerische Chemische Gesellschaft2016

Chiral N-Heterocyclic Carbene Ligand Enabled Nickel(0)-Catalyzed Enantioselective Three-Component Couplings as Direct Access to Silylated Indanols

Nicolai Cramer, Joachim Sven Ernst Ahlin

An enantioselective nickel(0)-catalyzed reductive three-component coupling between aromatic aldehydes, norbornenes, and silanes affords directly silyl-protected indanol derivatives. A new bulky chiral C-2-symmetric NHC (NHC = N-heterocyclic carbene) ligand ...

American Chemical Society2016

Chiral gamma-Lactams by Enantioselective Palladium(0)-Catalyzed Cyclopropane Functionalizations

Nicolai Cramer, Julia Pedroni

Cyclopropanes fused to pyrrolidines are important structural features found in a number of marketed drugs and development candidates. Typically, their synthesis involves the cyclopropanation of a dihydropyrrole precursor. Reported herein is a complementary ...

Wiley-VCH Verlag GmbH2015

Enantioselective palladium(0)-catalyzed intramolecular cyclopropane functionalization: access to dihydroquinolones, dihydroisoquinolones and the BMS-791325 ring system

Tanguy Jean Daniel Saget, Nicolai Cramer, Pavel Alexandrovich Donets, Julia Pedroni

Taddol-based phosphoramidite ligands enable enantioselective palladium(0)-catalyzed C-H arylation of cyclopropanes. The cyclized products are obtained in high yields and enantioselectivities. The reported method provides efficient access to a broad range o ...

Royal Soc Chemistry2015

Chiral Cyclopentadienyl Ligands Enable a Rhodium(III)-Catalyzed Enantioselective Access to Hydroxychromanes and Phthalides

Baihua Ye, Nicolai Cramer

The demand for efficient chiral cyclopentadienyl ligands (Cp-x) has increased significantly in recent years, partly because Cp*Rh(III) species have been developed as powerful catalysts for directed C-H functionalization reactions. However, a lack of suitab ...

Georg Thieme Verlag Kg2015

Chiral Cyclopentadienyl Iridium(III) Complexes Promote Enantioselective Cycloisomerizations Giving Fused Cyclopropanes

Nicolai Cramer, Michael Christian Dieckmann, Yun-Suk Jang

The cyclopentadienyl (Cp) group is a very important ligand for many transition-metal complexes which have been applied in catalysis. The availability of chiral cyclopentadienyl ligands (Cp-x) lags behind other ligand classes, thus hampering the investigati ...

Wiley-VCH Verlag GmbH2015

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