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Nicolai Cramer

Cette personne a quitté l’EPFL

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Publications associées (113)

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Regiodivergent Cyclobutanone Cleavage: Switching Selectivity with Different Lewis Acids

Nicolai Cramer, Laetitia Marie Mélanie Souillart

The exploitation of strain release in small rings as driving force to enable complex transformations is a powerful synthetic tool. Among them, cyclobutanones are particularly versatile substrates that can be elaborated in a wide variety of structurally div ...

Wiley-Blackwell2015

Exploitation of Unconventional Electrophiles in Enantioselective Pd(0)-Catalyzed C-H Functionalizations

Nicolai Cramer, Daria Grosheva

Asymmetric metal-catalyzed C-H functionalization is a powerful strategy for the rapid generation of complex target molecules from simple precursors. While aryl (pseudo) halides have been used as electrophilic substrates in enantioselective Pd(0)-catalyzed ...

2019

Enantioselective Iron-Catalyzed Cross-[4+4]-Cycloaddition of 1,3-Dienes Provides Chiral Cyclooctadienes

Alissa Cordula Götzinger, Nicolai Cramer, Elena Braconi

Chiral cyclooctadienes are a frequently occurring scaffold in natural products and specialty chemicals, and are used as ligands in asymmetric catalysis. Accessing substituted cyclooctadienes in an efficient asymmetric fashion has been notoriously challengi ...

2020

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

Convenient Preparation of Tri-tert-butylphosphonium Tetrafluoroborate

Nicolai Cramer, Tanguy Jean Daniel Saget

The versatile tri-tert-butylphosphonium tetrafluoroborate ligand is prepared in a convenient, simple, and high-yielding procedure without the isolation of sensitive intermediates. ...

2011

Alkynyl triazenes enable divergent syntheses of 2-pyrones

Kay Severin, Nicolai Cramer, Carl Thomas Bormann, Jin Fay Tan

The 2-pyrone motif occurs frequently in bioactive natural products and is appreciated as synthetic intermediates. However, only few methods allow for diversifying functional group modifications on this relevant heterocycle. The distinct properties of 1-alk ...

2021

Chemo- and regio-divergent access to fluorinated 1-alkyl and 1-acyl triazenes from alkynyl triazenes

Kay Severin, Nicolai Cramer, Carl Thomas Bormann, Jin Fay Tan

The 1,1,2,2-tetrafluoroethylene unit is prevalent in bioactive molecules and functional materials. Despite being in principle a straightforward strategy to access this motif, the direct tetrafluorination of alkynes involves very hazardous or inconvenient r ...

2022

Chiral Cyclopentadienyls: Enabling Ligands for Asymmetric Rh(III)-Catalyzed C-H Functionalizations

Nicolai Cramer, Baihua Ye

Transition-metal catalyzed C-H functionalizations became a complementary and efficient bond-forming strategy over the past decade. In this respect, Cp*Rh(III) complexes have emerged as powerful catalysts for a broad spectrum of reactions giving access to s ...

American Chemical Society2015

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

Nicolai Cramer, Yun-Suk Jang, Michael Christian Dieckmann

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

Ligand-Controlled Regiodivergent Pathways of Rhodium(III)-Catalyzed Dihydroisoquinolone Synthesis: Experimental and Computational Studies of Different Cyclopentadienyl Ligands

Anne-Clémence Corminboeuf, Nicolai Cramer, Matthew Wodrich, Jérôme Florian Gonthier, Baihua Ye

Rh-III-catalyzed directed C-H functionalizations of arylhydroxamates have become a valuable synthetic tool. To date, the regioselectivity of the insertion of the unsaturated acceptor into the common cyclometalated intermediate was dependent solely on intri ...

Wiley-V C H Verlag Gmbh2014

Enantioselective Ruthenium(II)-Catalyzed Access to Benzonorcaradienes by Coupling of Oxabenzonorbornadienes and Alkynes

Nicolai Cramer, Shouguo Wang, Sung Hwan Park

Benzonorcaradienes and benzonorcarenes are attractive scaffolds that occur in natural products as well as biologically active compounds. However, there is a significant gap in the current synthetic toolbox as methods to access benzonorcaradiene enantiosele ...

2019

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

Nicolai Cramer, Baihua Ye

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

Catalytic Enantioselective Functionalizations of C-H Bonds by Chiral Iridium Complexes

Vitalii Smal, Nicolai Cramer, Jin Fay Tan, Lukasz Piotr Wozniak, Adrien Jules Louis Madron Du Vigné, Qui-Hien Nguyen

The development of catalytic enantioselective transformations, enabling the construction of complex molecular scaffolds from simple precursors, has been a long-standing challenge in organic synthesis. Recent achievements in transition-metal catalyzed enant ...

2020

A 1,3,2-Diazaphospholene-Catalyzed Reductive Claisen Rearrangement

Nicolai Cramer, Pavel Alexandrovich Donets, John Henry Reed, Solène Florie Miaskiewicz

1,3,2-Diazaphospholenes (DAPs) are an emerging class of organic hydrides. In this work, we exploited them as efficient catalysts for very mild reductive Claisen rearrangements. The method is tolerant towards a wide variety of functional groups and operates ...

Wiley-VCH Verlag GmbH2019

Enantioselective Synthesis of Chiral-at-Sulfur 1,2-Benzothiazines by (CpRhIII)-Rh-x-Catalyzed C-H Functionalization of Sulfoximines

Nicolai Cramer, Yang Sun

Sulfoximines with stereogenic sulfur atoms are attractive structural motifs in drug discovery. A direct catalytic enantioselective method for the synthesis of sulfur-chiral 1,2-benzothiazines from readily accessible diaryl sulfoximines is presented. Rhodiu ...

Wiley-VCH Verlag GmbH2018

Diaminophosphine Oxide Ligand Enabled Asymmetric Nickel-Catalyzed Hydrocarbamoylations of Alkenes

Nicolai Cramer, Pavel Alexandrovich Donets

Chiral trivalent phosphorus species are the dominant class of ligands and the key controlling element in asymmetric homogeneous transition-metal catalysis. Here, novel chiral diaminophosphine oxide ligands are described. The arising catalyst system with ni ...

Amer Chemical Soc2013

Enantioselective Rhodium-catalyzed C-C Bond Activation of Cyclobutanones

Nicolai Cramer, Laetitia Marie Mélanie Souillart

The activation of carbon-carbon bonds has attracted much attention in the past decade. Despite important progress, the development of asymmetric reactions lags behind. For the first time, asymmetric rhodium(I)-catalyzed direct oxidative additions into enan ...

Swiss Chemical Soc2015

Streamlined synthetic assembly of α-chiral CAAC ligands and catalytic performance of their copper and ruthenium complexes

Nicolai Cramer, Adrien Jules Louis Madron Du Vigné

The unique electronic and steric parameters of chiral cyclic alkyl amino carbene (CAAC) ligands render them appealing steering ligands for enantioselective transition-metal catalyzed transformations. Due to the lack of efficient synthetic strategies to acc ...

2024

Nickel(0)-Catalyzed Enantioselective Annulations of Alkynes and Arylenoates Enabled by a Chiral NHC Ligand: Efficient Access to Cyclopentenones

Nicolai Cramer, Pavel Alexandrovich Donets, Joachim Sven Ernst Ahlin

Cyclopentenones are versatile structural motifs of natural products as well as reactive synthetic intermediates. The nickel-catalyzed reductive [3+2] cycloaddition of alpha,beta-unsaturated aromatic esters and alkynes constitutes an efficient method for th ...

Wiley-Blackwell2014

Asymmetric (CpRh)-Rh-x(III)-Catalyzed Acrylic Acid C-H Functionalization with Allenes Provides Chiral gamma-Lactones

Nicolai Cramer, Shouguo Wang

A chiral cyclopentadienyl (Cp-x) ligand featuring the semi-saturated H8-binaphthyl backbone as the chiral element was developed. Its application potential was demonstrated by (CpRhIII)-Rh-x-catalyzed C-H bond functionalization of acryl acids and allenes, e ...

AMER CHEMICAL SOC2020