Vittorio Pace

2-Methyltetrahydrofuran (2-MeTHF): A Biomass-Derived Solvent with Broad Application in Organic Chemistry

2-Methyl-tetrahydrofuran (2-MeTHF) can be derived from renewable resources (e.g., furfural or levulinic acid) and is a promising alternative solvent in the search for environmentally benign synthesis strategies. Its physical and chemical properties, such as its low miscibility with water, boiling point, remarkable stability compared to other cyclic-based solvents such as THF, and others make it appealing for applications in syntheses involving organometallics, organocatalysis, and biotransformations or for processing lignocellulosic materials. Interestingly, a significant number of industries have also started to assess 2-MeTHF in several synthetic procedures, often with excellent results and prospects. Likewise, preliminary toxicology assessments suggest that the use of 2-MeTHF might even be extended to more processes in pharmaceutical chemistry. This Minireview describes the properties of 2-MeTHF, the state-of-the-art of its use in synthesis, and covers several outstanding examples of its application from both industry and academia.

Chemoselective Activation Strategies of Amidic Carbonyls towards Nucleophilic Reagents

Important advancements have been made in recent years in the development of chemoselective additions of nucleophiles to well known inert amide carbonyls in the presence of multi-electrophilic substrates. Herein, we present the most relevant results showing how carbonyl amides can be chemoselectively functionalised in the presence of electrophilic functionalities such as Weinreb amides.

2-Methyltetrahydrofuran as a suitable green solvent for phthalimide functionalization promoted by supported KF

An efficient chemoselective nitrogen functionalization of phthalimides by using KF-Alumina in 2-methyltetrahydrofuran, a solvent obtained from renewal sources, is described.

Cu(I)–NHC Catalyzed Asymmetric Silyl Transfer to Unsaturated Lactams and Amides

The first asymmetric silylation of unsaturated lactams and amides using Cu(I)-NHC catalysts and PhMe2SiBpin has been accomplished. The method has been exploited in an expedient asymmetric synthesis of the (R)-enantiomer of the nootropic drug oxiracetam.

Addition of lithium carbenoids to isocyanates: a direct access to synthetically useful N-substituted 2-haloacetamides.

The addition of lithium carbenoids to isocyanates provides a versatile access to N-substituted 2-haloacetamides: the reaction tolerates the presence of variously functionalized substituents on the nitrogen atom, including sterically demanding ones and reactive halogens. No erosion of the enantiopurity was observed in the case of optically active isocyanates. One of the substrates prepared has been employed in Charettes type chemoselective addition of a Grignard reagent to access an α-chloroketone.

Structures of Highly Twisted Amides Relevant to Amide N-C Cross-Coupling: Evidence for Ground-State Amide Destabilization.

Herein, we show that acyclic amides that have recently enabled a series of elusive transition-metal-catalyzed N-C activation/cross-coupling reactions are highly twisted around the N-C(O) axis by a new destabilization mechanism of the amide bond. A unique effect of the N-glutarimide substituent, leading to uniformly high twist (ca. 90°) irrespective of the steric effect at the carbon side of the amide bond has been found. This represents the first example of a twisted amide that does not bear significant steric hindrance at the α-carbon atom. The (15) N NMR data show linear correlations between electron density at nitrogen and amide bond twist. This study strongly supports the concept of amide bond ground-state twist as a blueprint for activation of amides toward N-C bond cleavage. The new mechanism offers considerable opportunities for organic synthesis and biological processes involving non-planar amide bonds.

2-Methyltetrahydrofuran: A Versatile Eco-Friendly Alternative to THF in Organometallic Chemistry

Vittorio Pace received a degree in pharmacy from the University of Perugia (Italy) in 2005 and aM.Sc. in drug design and development from the University of Pavia (Italy) in 2008. He obtained his Ph.D. in chemistry under the guidance of Professor A. R. Alcantara at the Complutense University of Madrid (2010). He then moved to the University of Vienna (Austria) as a postdoctoral Ernst Mach fellow with Professor W. Holzer and from September 2011 joined the group of Professor D. Procter at the University of Manchester (UK) for a second postdoctoral position.

Chemoselective Schwartz Reagent Mediated Reduction of Isocyanates to Formamides

Addition of the in situ generated Schwartz reagent to widely available isocyanates constitutes a chemoselective, high-yielding, and versatile approach to the synthesis of variously functionalized formamides. Steric and electronic factors or the presence of sensitive functionalities (esters, nitro groups, nitriles, alkenes) do not compromise the potential of the method. Full preservation of the stereochemical information contained in the starting materials is observed. The use of formamides in the nucleophilic addition of organometallic reagents (Chida-Sato allylation, Charette-Huang addition to imidoyl triflate activated amides, Matteson homologation of boronic esters) is briefly investigated.

Highly efficient chemoselective N-TBS protection of anilines under exceptional mild conditions in the eco-friendly solvent 2-methyltetrahydrofuran

A straightforward chemoselective protection of anilines as N-TBS derivatives is described by using a suitable deprotonation of the amine with methyllithium in the environmentally friendly and safer substitute of THF, 2-methyltetrahydrofuran, under exceptional mild reaction conditions (0 °C, 30 min). Interestingly, the protecting group maybe cleaved efficiently by simple treatment of N-TBS-anilines with silica gel in ethanol–water.

A Robust, Eco‐Friendly Access to Secondary Thioamides through the Addition of Organolithium Reagents to Isothiocyanates in Cyclopentyl Methyl Ether (CPME)

The nucleophilic addition of widely available and variously functionalized organolithium reagents to isothiocyanates represents a straightforward, high-yielding, one-pot method to access secondary thioamides. The simple reaction conditions required and the broad scope (>50 cases examples) makes it a robust and reliable method to access both simple and complex thioamides, including enantiopure ones. Noxious and unpleasant-smelling sulfurating agents, usually employed in the literature established methods, are avoided during the whole synthetic procedure thus, rendering the protocol highly attractive, also for sustainability aspects.