Martin Oestreich

Bio: Martin Oestreich is an academic researcher from Technical University of Berlin. The author has contributed to research in topics: Enantioselective synthesis & Lewis acids and bases. The author has an hindex of 63, co-authored 454 publications receiving 13021 citations. Previous affiliations of Martin Oestreich include University of Freiburg & Centre national de la recherche scientifique.

The Mizoroki–Heck Reaction

Abstract: Foreword by Professor Richard F. Heck 1 Mechanisms of the Mizoroki-Heck Reaction Anny Jutand 2 Focus on Catalyst Development and Ligand Design Irina P. Beletskaya and Andrei V. Cheprakov 3 Focus on Regioselectivity and Product Outcome in Organic Synthesis Peter Nilsson, Kristofer Olofsson and Mats Larhed 4 Waste-Minimized Mizoroki-Heck Reactions Lukas Goo ss en and Kathe Goo ss en 5 Formation of Carbocycles Axel B. Machotta and Martin Oestreich 6 Formation of Heterocycles Thierry Muller and Stefan Brase 7 Chelation-Controlled Mizoroki-Heck Reactions Kenichiro Itami and Jun-ichi Yoshida 8 The Mizoroki-Heck Reaction in Domino Processes Lutz F. Tietze and Laura M. Levy 9 Oxidative Heck-Type Reactions (Fujiwara-Moritani Reactions) Eric M. Ferreira, Haiming Zhang and Brian M. Stoltz 10 Mizoroki-Heck Reactions with Metals Other than Palladium Lutz Ackermann and Robert Born 11 Ligand Design for Intermolecular Asymmetric Mizoroki-Heck Reactions Anthony G. Coyne, Martin O. Fitzpatrick and Patrick J. Guiry 12 Intramolecular Enantioselective Mizoroki-Heck Reactions James T. Link and Carol K. Wada 13 Desymmetrizing Heck Reactions Masakatsu Shibasaki and Takashi Ohshima 14 Combinatorial and Solid-Phase Syntheses Thierry Muller and Stefan Brase 15 Mizoroki-Heck Reactions: Modern Solvent Systems and Reaction Techniques Werner Bonrath, Ulla L'etinois, Thomas Netscher and Jan Schutz 16 The Asymmetric Intramolecular Mizoroki-Heck Reaction in Natural Product Total Synthesis Amy B. Dounay and Larry E. Overman

A unified survey of Si–H and H–H bond activation catalysed by electron-deficient boranes

Abstract: The bond activation chemistry of B(C6F5)3 and related electron-deficient boranes is currently experiencing a renaissance due to the fascinating development of frustrated Lewis pairs (FLPs). B(C6F5)3's ability to catalytically activate Si–H bonds through η1 coordination opened the door to several unique reduction processes. The ground-breaking finding that the same family of fully or partially fluorinated boron Lewis acids allows for the related H–H bond activation, either alone or as a component of an FLP, brought considerable momentum into the area of transition-metal-free hydrogenation and, likewise, hydrosilylation. This review comprehensively summarises synthetic methods involving borane-catalysed Si–H and H–H bond activation. Systems corresponding to an FLP-type situation are not covered. Aside from the broad manifold of CX bond reductions and CX/C–X defunctionalisations, dehydrogenative (oxidative) Si–H couplings are also included.

Main-Group Lewis Acids for C–F Bond Activation

Abstract: The significant benefits of fluorinated compounds have inspired the development of diverse techniques for the activation and subsequent (de)functionalization of rather inert C–F bonds. Although substantial progress has been made in the selective activation of C(sp2)–F bonds employing transition metal complexes, protocols that address nonactivated C(sp3)–F bonds are much less established. In this regard, the use of strong main-group Lewis acids has emerged as a powerful tool to selectively activate C(sp3)–F bonds in saturated fluorocarbons. This Perspective provides a concise overview of various cationic and neutral silicon-, boron-, and aluminum-based Lewis acids that have been identified to facilitate the heterolytic fluoride abstraction from aliphatic fluorides. The potential of these Lewis acids in hydrodefluorination as well as defluorinative C–F bond functionalization reactions is highlighted. Emphasis is placed on the underlying mechanistic principles to provide a systematic classification of the in...

Carboxylate-assisted transition-metal-catalyzed C-H bond functionalizations: mechanism and scope.

Abstract: The site-selective formation of carbon-carbon bonds through direct functionalizations of otherwise unreactive carbon-hydrogen bonds constitutes an economically attractive strategy for an overall streamlining of sustainable syntheses. In recent decades, intensive research efforts have led to the development of various reaction conditions for challenging C-H bond functionalizations, among which transition-metal-catalyzed transformations arguably constitute thus far the most valuable tool. For instance, the use of inter alia palladium, ruthenium, rhodium, copper, or iron complexes set the stage for chemo-, site-, diastereo-, and/or enantioselective C-H bond functionalizations. Key to success was generally a detailed mechanistic understanding of the elementary C-H bond metalation step, which depending on the nature of the metal fragment can proceed via several distinct reaction pathways. Traditionally, three different modes of action were primarily considered for CH bond metalations, namely, (i) oxidative addition with electronrich late transition metals, (ii) σ-bond metathesis with early transition metals, and (iii) electrophilic activation with electrondeficient late transition metals (Scheme 1). However, more recent mechanistic studies indicated the existence of a continuum of electrophilic, ambiphilic, and nucleophilic interactions. Within this continuum, detailed experimental and computational analysis provided strong evidence for novel C-H bond metalationmechanisms relying on the assistance of a bifunctional ligand bearing an additional Lewis-basic heteroatom, such as that found in (heteroatom-substituted) secondary phosphine oxides or most prominently carboxylates (Scheme 1, iv). This novel insight into the nature of stoichiometric metalations has served as stimulus for the development of novel transformations based on cocatalytic amounts of carboxylates, which significantly broadened the scope of C-H bond functionalizations in recent years, with most remarkable progress being made in palladiumor ruthenium-catalyzed direct arylations and direct alkylations. These carboxylate-assisted C-H bond transformations were mostly proposed to proceed via a mechanism in which metalation takes place via a concerted base-assisted deprotonation. To mechanistically differentiate these intramolecular metalations new acronyms have recently been introduced into the literature, such as CMD (concerted metalationdeprotonation), IES (internal electrophilic substitution), or AMLA (ambiphilic metal ligand activation), which describe related mechanisms and will be used below where appropriate. This review summarizes the development and scope of carboxylates as cocatalysts in transition-metal-catalyzed C-H functionalizations until autumn 2010. Moreover, experimental and computational studies on stoichiometric metalation reactions being of relevance to the mechanism of these catalytic processes are discussed as well. Mechanistically related C-H bond cleavage reactions with ruthenium or iridium complexes bearing monodentate ligands are, however, only covered with respect to their working mode, and transformations with stoichiometric amounts of simple acetate bases are solely included when their mechanism was suggested to proceed by acetate-assisted metalation.

Transition-metal-catalyzed direct arylation of (hetero)arenes by C-H bond cleavage.

Abstract: The area of transition-metal-catalyzed direct arylation through cleavage of CH bonds has undergone rapid development in recent years, and is becoming an increasingly viable alternative to traditional cross-coupling reactions with organometallic reagents In particular, palladium and ruthenium catalysts have been described that enable the direct arylation of (hetero)arenes with challenging coupling partners—including electrophilic aryl chlorides and tosylates as well as simple arenes in cross-dehydrogenative arylations Furthermore, less expensive copper, iron, and nickel complexes were recently shown to be effective for economically attractive direct arylations

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

Abstract: : The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Frustrated Lewis pairs: metal-free hydrogen activation and more.

Abstract: Sterically encumbered Lewis acid and Lewis base combinations do not undergo the ubiquitous neutralization reaction to form "classical" Lewis acid/Lewis base adducts. Rather, both the unquenched Lewis acidity and basicity of such sterically "frustrated Lewis pairs (FLPs)" is available to carry out unusual reactions. Typical examples of frustrated Lewis pairs are inter- or intramolecular combinations of bulky phosphines or amines with strongly electrophilic RB(C(6)F(5))(2) components. Many examples of such frustrated Lewis pairs are able to cleave dihydrogen heterolytically. The resulting H(+)/H(-) pairs (stabilized for example, in the form of the respective phosphonium cation/hydridoborate anion salts) serve as active metal-free catalysts for the hydrogenation of, for example, bulky imines, enamines, or enol ethers. Frustrated Lewis pairs also react with alkenes, aldehydes, and a variety of other small molecules, including carbon dioxide, in cooperative three-component reactions, offering new strategies for synthetic chemistry.