Wouter Debrouwer

Bio: Wouter Debrouwer is an academic researcher from Ghent University. The author has contributed to research in topics: Hydroamination & Nucleophile. The author has an hindex of 7, co-authored 18 publications receiving 269 citations.

Preparation of phosphines through C-P bond formation.

Abstract: Phosphines are an important class of ligands in the field of metal-catalysis. This has spurred the development of new routes toward functionalized phosphines. Some of the most important C–P bond formation strategies were reviewed and organized according to the hybridization of carbon in the newly formed C–P bond.

Homogeneous Gold-Catalyzed Cyclization Reactions of Alkynes with N- and S-Nucleophiles

Abstract: This review covers the formation of N- and S-containing heterocycles, initiated by gold-catalyzed nucleophilic attack of N- or S-nucleophiles onto alkynes. These types of nucleophiles have been somewhat overlooked as compared to their C- or O-counterparts in other reviews. In this particular work, their intramolecular gold-mediated attack onto alkynes is reviewed in depth. It is structured in such a fashion that the reader will get a clear view of which substrates react in which cyclization mode.

Preparation of tetrasubstituted 3-phosphonopyrroles through hydroamination: scope and limitations.

Abstract: Phosphonylated pyrroles were obtained by a ZnCl2-catalyzed 5-exo-dig hydroamination of propargylic enamines. These starting compounds were obtained in two steps from commercially available β-ketophosphonates. The method tolerates a wide variety of substituents at the 1,2- and 5-position of the pyrrole, while further derivatization allows for the introduction of substituents at the 4-position via lithiation or halogenation.

Gold(I)-Catalyzed Activation of Alkynes for the Construction of Molecular Complexity

Abstract: 1.1. General Reactivity of Alkyne-Gold(I) Complexes For centuries, gold had been considered a precious, purely decorative inert metal. It was not until 1986 that Ito and Hayashi described the first application of gold(I) in homogeneous catalysis.1 More than one decade later, the first examples of gold(I) activation of alkynes were reported by Teles2 and Tanaka,3 revealing the potential of gold(I) in organic synthesis. Now, gold(I) complexes are the most effective catalysts for the electrophilic activation of alkynes under homogeneous conditions, and a broad range of versatile synthetic tools have been developed for the construction of carbon–carbon or carbon–heteroatom bonds. Gold(I) complexes selectively activate π-bonds of alkynes in complex molecular settings,4−10 which has been attributed to relativistic effects.11−13 In general, no other electrophilic late transition metal shows the breadth of synthetic applications of homogeneous gold(I) catalysts, although in occasions less Lewis acidic Pt(II) or Ag(I) complexes can be used as an alternative,9,10,14,15 particularly in the context of the activation of alkenes.16,17 Highly electrophilic Ga(III)18−22 and In(III)23,24 salts can also be used as catalysts, although often higher catalyst loadings are required. In general, the nucleophilic Markovnikov attack to η2-[AuL]+-activated alkynes 1 forms trans-alkenyl-gold complexes 2 as intermediates (Scheme 1).4,5a,9,10,12,25−29 This activation mode also occurs in gold-catalyzed cycloisomerizations of 1,n-enynes and in hydroarylation reactions, in which the alkene or the arene act as the nucleophile. Scheme 1 Anti-Nucleophilic Attack to η2-[AuL]+-Activated Alkynes

Progress in the Chemistry of Tetrahydroquinolines.

Abstract: Tetrahydroquinoline is one of the most important simple nitrogen heterocycles, being widespread in nature and present in a broad variety of pharmacologically active compounds. This Review summarizes the progress achieved in the chemistry of tetrahydroquinolines, with emphasis on their synthesis, during the period from mid-2010 to early 2018.

C–P Bond-Forming Reactions via C–O/P–H Cross-Coupling Catalyzed by Nickel

Abstract: The first Ni-catalyzed C–O/P–H cross-coupling producing organophosphorus compounds is disclosed. This method features wide generality in regard to both C–O and P–H compounds: for C–O compounds, the readily available alcohol derivatives of aryl, alkenyl, benzyl, and allyl are applicable, and for P–H compounds, both >PV(O)H compounds (secondary phosphine oxide, H-phosphinate, and H-phosphonate) and hydrogen phosphines (>PIIIH) can be used as the substrates. Thus, a variety of valuable C(sp2)–P and C(sp3)–P compounds can be readily obtained in good to excellent yields by this new strategy.

Palladium-catalyzed carbon-sulfur or carbon-phosphorus bond metathesis by reversible arylation

Abstract: Compounds bearing aryl-sulfur and aryl-phosphorus bonds have found numerous applications in drug development, organic materials, polymer science, and homogeneous catalysis. We describe palladium-catalyzed metathesis reactions of both compound classes, each of which proceeds through a reversible arylation manifold. The synthetic power and immediate utility of this approach are demonstrated in several applications that would be challenging to achieve by means of traditional cross-coupling methods. The C(sp2)-S bond metathesis protocol was used in the depolymerization of a commercial thermoplastic polymer and in the late-stage derivatization of a drug. The C(sp2)-P variant led to the convenient preparation of a variety of phosphorus heterocycles, including a potential chiral ligand and fluorescent organic materials, via a ring-closing transformation.

Gold-Catalyzed Reactions of Specially Activated Alkynes, Allenes, and Alkenes

Abstract: This review describes the gold-catalyzed reactions of specially activated alkynes, allenes, and alkenes. Such species are characterized by the presence of either electron-donating or electron-withdrawing groups as substituents of the carbon π-system. They are intrinsically polarized, and when compared to their nonspecially activated counterparts can therefore be involved in gold-catalyzed transformations featuring increased regio-, stereo-, and chemoselectivities. The chemistry of specially activated carbon π-systems under homogeneous gold catalysis is extremely rich and varied. The reactivity observed with nonspecially activated unsaturated systems can often be transposed to specially activated ones without loss of efficiency. However, specially activated carbon π-systems also exhibit specific reactivities that cannot be attained with regular substrates. In this family of carbon π-systems, ynamides and their analogs, along with alkynyl carbonyl derivatives, are the classes of substrates that have retained the most attention. This review provides an overview of the chemistry developed with all classes of specially activated carbon π-systems by discussing their general and specific reactivities, presenting and commenting on their gold-catalyzed transformations as well as their applications.