Publications by Stefano Nicolai

Lewis acid catalyzed [4+2] annulation of bicyclobutanes with dienol ethers for the synthesis of bicyclo[4.1.1]octanes

Bicyclic carbocycles containing a high fraction of Csp3 have become highly attractive synthetic targets because of the multiple applications they have found in medicinal chemistry. The formal cycloaddition of bicyclobutanes (BCBs) with two- or three-atom p ...

Royal Soc Chemistry2024

X-Ray and NMR Structural Data of Ethynylbenziodoxolones (EBXs) Reagents and Their Analogues

Rosario Scopelliti, Matthew Wodrich, Jérôme Waser, Stefano Nicolai, Farzaneh Fadaei Tirani, Durga Prasada Rao Hari, Eliott Hugo Joran Le Du, Nieves Pilar Ramirez Hernandez

First synthesized in 1991, EthynylBenziodoXolones (EBXs) - cyclic hypervalent iodine reagents derived from 2-iodobenzoic acid - are now among the most versatile electrophilic alkynylation reagents. Due to their cyclic structure, these reagents exhibit enha ...

WILEY-V C H VERLAG GMBH2023

Cysteine-Cysteine Cross-Conjugation of both Peptides and Proteins with a Bifunctional Hypervalent Iodine-Electrophilic Reagent

Jérôme Waser, Stefano Nicolai, Abhaya Kumar Mishra

Peptide and protein bioconjugation sees ever-growing applications in the pharmaceutical sector. Novel strategies and reagents that can address the chemo- and regioselectivity issues inherent to these biomolecules, while delivering stable and functionalizab ...

2023

(4+3) Annulation of Donor-Acceptor Cyclopropanes and Azadienes: Highly Stereoselective Synthesis of Azepanones

Jérôme Waser, Stefano Nicolai

Azepanes are important seven-membered heterocycles, which are present in numerous natural and synthetic compounds. However, the development of convergent synthetic methods to access them remains challenging. Herein, we report the Lewis acid catalyzed (4+3) ...

Wiley-VCH Verlag GmbH2022

Pd(II)-Catalyzed Aminoacetoxylation of Alkenes Via Tether Formation

Jérôme Waser, Stefano Nicolai, Ashis Kumar Das, Thomas Rossolini

A Pd-catalyzed method based on the use of a molecular tether is described for olefin difunctionalization. Enabled by an easily introduced trifluoroacetaldehyde-derived tether, a simultaneous introduction of oxygen and nitrogen heteroatoms across unsaturate ...

2022

Photocatalytic Umpolung of N- and O-substituted alkenes for the synthesis of 1,2-amino alcohols and diols

Jérôme Waser, Stefano Nicolai, Stephanie Grace Elizabeth Amos

We report an organophotocatalytic 1,2-oxyalkynylation of ene-carbamates and enol ethers using Ethynyl BenziodoXolones (EBXs). 1-Alkynyl-1,2-amino alcohols and diols were obtained in up to 89% yield. Photocatalytic formation of radical cations led to Umpolu ...

2020

Palladium-Catalyzed Functionalization of Olefins and Alkynes: From Oxyalkynylation to Tethered Dynamic Kinetic Asymmetric Transformations (DYKAT)

Jérôme Waser, Stefano Nicolai, Ugo Jonathan Orcel, Phillip Gulliver Dominic Greenwood, Bastian Antoine Rodolphe Claude Muriel, Luca Buzzetti, Mikus Purins

This review presents an account of the palladium-catalyzed functionalizations of alkenes and alkynes developed at the Laboratory of Catalysis and Organic Synthesis (LCSO). Starting from the intramolecular oxy- and aminoalkynylation of alkenes, tethered met ...

2020

One-Pot Synthesis of 1-[(Triisopropylsilyl)ethynyl]-1,2-benziodoxol-3(1H)-one (TIPS-EBX): Process Safety Assessment and Impact of Impurities on Product Stability

Jérôme Waser, Stefano Nicolai, Lionel Schouwey, Durga Prasada Rao Hari, Paola Caramenti, Miyeon Chang

The hypervalent iodine reagent 1-[(TriIsoPropylSilyl)Ethynyl]-1,2-BenziodoXol-3(1H)-one (TIPS-EBX) is among the most useful electrophilic and somophilic alkynylation reagents. Herein, we report a new synthetic protocol to access this reagent in one step fr ...

2019

Metal-Free Electrophilic Alkynylation of Sulfenate Anions with Ethynylbenziodoxolone Reagents

Jérôme Waser, Stefano Nicolai, Franck Le Vaillant, Alec Gagnebin, Stephanie Grace Elizabeth Amos

Alkynyl sulfoxides are important building blocks with a unique reactivity in organic chemistry, but only a few reliable methods have been reported to synthesize them. A novel route to access alkynyl sulfoxides is reported herein by using ethynyl benziodoxo ...

2019

Cyclic Hypervalent Iodine Reagents for Azidation: Safer Reagents and Photoredox-Catalyzed Ring Expansion

Thierry Meyer, Jérôme Waser, Stefano Nicolai, Raphaël Michel Henri Simonet-Davin, Annik Nanchen, Sébastien Pierre Louis Alazet, Johannes Preindl

Azides are building blocks of increasing importance in synthetic chemistry, chemical biology, and materials science. Azidobenziodoxolone (ABX, Zhdankin reagent) is a valuable azide source, but its safety profile has not been thoroughly established. Herein, ...

2018

Fine-Tuned Organic Photoredox Catalysts for Fragmentation-Alkynylation Cascades of Cyclic Oxime Ethers

Jérôme Waser, Stefano Nicolai, Ganna Gryn'ova, Franck Le Vaillant, Marion Marie-Agnès Garreau

2018

Indole- and Pyrrole-BX: Bench-Stable Hypervalent Iodine Reagents for Heterocycle Umpolung

Jérôme Waser, Stefano Nicolai, Paola Caramenti

The one-step synthesis of the bench-stable hypervalent iodine reagents IndoleBX and PyrroleBX using mild Lewis acid catalyzed conditions is reported. The new reagents are stable up to 150 degrees C and were applied in the C-H arylation of unactivated arene ...

2017

Divergent Access to (1,1) and (1,2)-Azidolactones from Alkenes using Hypervalent Iodine Reagents

Jérôme Waser, Stefano Nicolai, Thibaut Christian Courant, Franck Le Vaillant, Sébastien Pierre Louis Alazet

A versatile synthesis of azidolactones through azidation and cyclization of carboxylic acids onto alkenes has been developed. Based on either photoredox or palladium catalysis, (1,1) and (1,2) azido lactones can be selectively synthesized. The choice of ca ...

2017

Intramolecular palladium-catalyzed alkene carboalkynylation

Jérôme Waser, Stefano Nicolai, Peter Swallow

Carbocycles are essential building blocks for the synthesis of natural and synthetic bioactive compounds. Herein, we report the first example of palladium-catalyzed intramolecular carboalkynylation of non-activated olefins. Using activated carbonyl compoun ...

Elsevier2015

Pd(0)-Catalyzed Alkene Oxy- and Aminoalkynylation with Aliphatic Bromoacetylenes

Raha Sedigh-Zadeh, Jérôme Waser, Stefano Nicolai

Tetrahydrofurans and pyrrolidines are among the most important heterocycles found in bioactive compounds. Cyclization-functionalization domino reactions of alcohols or amines onto olefins,constitute one of the most efficient methods to access them. In this ...

American Chemical Society2013

Pd-Catalyzed Oxy- and Aminoalkynylation of Olefins

Stefano Nicolai

EPFL2013

Cyclopropanes and Hypervalent Iodine Reagents: High Energy Compounds for Applications in Synthesis and Catalysis

Davinia Fernández González, Jérôme Waser, Filippo De Simone, Jonathan Brand, Stefano Nicolai

One of the major challenges faced by organic chemistry is the efficient synthesis of increasingly complex molecules. Since October 2007, the Laboratory of Catalysis and Organic Synthesis (LCSO) at EPFL has been working on the development of catalytic react ...

2011

Benziodoxole-based hypervalent iodine reagents for atom-transfer reactions

Davinia Fernández González, Jérôme Waser, Jonathan Brand, Stefano Nicolai

In the last decades, hypervalent iodine reagents have raised from chemical curiosities to mainstream reagents in organic synthesis. The use of benziodoxole-derived reagents has been especially successful in oxidation methods, whereas non-cyclic iodinanes h ...

Royal Society of Chemistry2011

A Palladium-Catalyzed Aminoalkynylation Strategy towards Bicyclic Heterocycles: Synthesis of (±)-Trachelanthamidine

Jérôme Waser, Cyril Piemontesi, Stefano Nicolai

Sweet cyclizations: The synthesis of pyrrolizidines and indolizidines has been achieved. Olefins were subjected to an intramolecular palladium-catalyzed aminoalkynylation with the hypervalent iodine reagent TIPS-EBX. After removal of the protecting group, ...

Wiley-VCH Verlag GmbH2011

Benziodoxole-based hypervalent iodine reagents for atom-transfer reactions

Davinia Fernández González, Jérôme Waser, Jonathan Brand, Stefano Nicolai

In the last decades, hypervalent iodine reagents have raised from chemical curiosities to mainstream reagents in organic synthesis. The use of benziodoxole-derived reagents has been especially successful in oxidation methods, whereas non-cyclic iodinanes h ...

Royal Society of Chemistry2011