1
|
Wang C, Wu J, Yan B, Ni C, Ma X, Yang Z. N
‐coordinated Aluminum Complexes Catalyze the Hydrostannation of Alkynes. ChemistrySelect 2023. [DOI: 10.1002/slct.202204405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- Chengzhi Wang
- School of Chemistry and Chemical Engineering Beijing Institute of Technology Beijing 100081 P. R. China
| | - Jin Wu
- Xi'an Aerospace Propulsion Test Technique Institute Xi'an 710100 P. R. China
| | - Ben Yan
- School of Chemistry and Chemical Engineering Beijing Institute of Technology Beijing 100081 P. R. China
| | - Congjian Ni
- School of Chemistry and Chemical Engineering Beijing Institute of Technology Beijing 100081 P. R. China
| | - Xiaoli Ma
- School of Chemistry and Chemical Engineering Beijing Institute of Technology Beijing 100081 P. R. China
| | - Zhi Yang
- School of Chemistry and Chemical Engineering Beijing Institute of Technology Beijing 100081 P. R. China
| |
Collapse
|
2
|
Wirtz L, Ghulam KY, Morgenstern B, Schäfer A. Constrained Geometry
ansa
‐Half‐Sandwich Complexes of Magnesium – Versatile
s
‐Block Catalysts. ChemCatChem 2022. [DOI: 10.1002/cctc.202201007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Lisa Wirtz
- Faculty of Natural Science and Technology Department of Chemistry Saarland University Campus Saarbrücken 66123 Saarbrücken Germany
| | - Kinza Yasmin Ghulam
- Faculty of Natural Science and Technology Department of Chemistry Saarland University Campus Saarbrücken 66123 Saarbrücken Germany
| | - Bernd Morgenstern
- Faculty of Natural Science and Technology Department of Chemistry Saarland University Campus Saarbrücken 66123 Saarbrücken Germany
| | - André Schäfer
- Faculty of Natural Science and Technology Department of Chemistry Saarland University Campus Saarbrücken 66123 Saarbrücken Germany
| |
Collapse
|
3
|
Pearce KG, Dinoi C, Hill MS, Mahon MF, Maron L, Schwamm RS, Wilson ASS. Synthesis of Molecular Phenylcalcium Derivatives: Application to the Formation of Biaryls. Angew Chem Int Ed Engl 2022; 61:e202200305. [PMID: 35212128 PMCID: PMC9315018 DOI: 10.1002/anie.202200305] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Indexed: 12/17/2022]
Abstract
Hydrocarbon‐soluble β‐diketiminato phenylcalcium derivatives, which display various modes of Ca−μ2‐Ph−Ca bridging, are accessible from reactions of Ph2Hg and [(BDI)CaH]2. Although the resultant compounds are inert toward the C−H bonds of benzene, they yield selective and uncatalyzed biaryl formation when reacted with readily available aryl bromides.
Collapse
Affiliation(s)
- Kyle G Pearce
- Department of Chemistry, University of Bath, Claverton Down, Bath, UK
| | - Chiara Dinoi
- Université de Toulouse et CNRS, INSA, UPS, UMR 5215, LPCNO, 135 Avenue de Rangueil, 31077, Toulouse, France
| | - Michael S Hill
- Department of Chemistry, University of Bath, Claverton Down, Bath, UK
| | - Mary F Mahon
- Department of Chemistry, University of Bath, Claverton Down, Bath, UK
| | - Laurent Maron
- Université de Toulouse et CNRS, INSA, UPS, UMR 5215, LPCNO, 135 Avenue de Rangueil, 31077, Toulouse, France
| | - Ryan S Schwamm
- Department of Chemistry, University of Bath, Claverton Down, Bath, UK
| | - Andrew S S Wilson
- Department of Chemistry, University of Bath, Claverton Down, Bath, UK
| |
Collapse
|
4
|
Hill MS, Pearce KG, Dinoi C, Mahon MF, Maron L, Schwamm RS, Wilson ASS. Synthesis of Molecular Phenylcalcium Derivatives: Application to the Formation of Biaryls. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202200305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Michael Stephen Hill
- University of Bath Chemistry Department of ChemistryUniversity of BathClaverton Down BA2 7AY Bath UNITED KINGDOM
| | | | - Chiara Dinoi
- Toulouse 3 University: Universite Toulouse III Paul Sabatier Chemistry FRANCE
| | | | - Laurent Maron
- Toulouse 3 University: Universite Toulouse III Paul Sabatier Chemistry FRANCE
| | | | | |
Collapse
|
5
|
Chapple P, Roisnel T, Cordier M, Carpentier JF, Sarazin Y. Heteroleptic Carbazolato-Barium Hydroborates and a Related Separated Ion Pair. Polyhedron 2022. [DOI: 10.1016/j.poly.2022.115731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
6
|
Baguli S, Mondal S, Mandal C, Goswami S, Mukherjee D. Cyclopentadienyl Complexes of the Alkaline Earths in Light of the Periodic Trends. Chem Asian J 2022; 17:e202100962. [PMID: 34825506 DOI: 10.1002/asia.202100962] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/02/2021] [Indexed: 11/09/2022]
Abstract
The electron-rich cyclopentadienyl and the analogous indenyl and fluorenyl ligands (collectively denoted here as Cp') have been impactful in stabilizing electron-deficient metal centers including the highly electropositive alkaline earths. Being in the s-block, the group 2 metals follow a major periodic variation in their atomic and ionic properties which is reflected in those Cp' compounds. This article presents an overview of this class of compounds for all the five metals from beryllium to barium (radium is excluded for its radioactivity), highlighting their systematic variation.
Collapse
Affiliation(s)
- Sudip Baguli
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur Nadia, 741246, West Bengal, India
| | - Sumana Mondal
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur Nadia, 741246, West Bengal, India
| | - Chhotan Mandal
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur Nadia, 741246, West Bengal, India
| | - Santu Goswami
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur Nadia, 741246, West Bengal, India
| | - Debabrata Mukherjee
- Department of Chemical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur Nadia, 741246, West Bengal, India
| |
Collapse
|
7
|
Buchner MR, Thomas-Hargreaves LR. s-Block chemistry in weakly coordinating solvents. Dalton Trans 2021; 50:16916-16922. [PMID: 34738606 DOI: 10.1039/d1dt03443j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Alkaline earth metal catalysis has been a growing field in recent years. To enhance reactivity and to understand the metal-substrate interactions in more detail, reactions are increasingly carried out in weakly coordinating solvents. This article gives an overview over the two main approaches to facilitate this, which are either through the employment of highly dipolar haloaryls as solvents, or by increasing the solubility of the ligand systems. The resulting coordination modes and reactivities are presented together with the synthetic strategies. Additionally, the latest results of group 1 complex chemistry in aliphatic solvents are illustrated and future challenges are highlighted.
Collapse
Affiliation(s)
- Magnus R Buchner
- Anorganische Chemie, Nachwuchsgruppe Hauptgruppenmetallchemie, Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany.
| | - Lewis R Thomas-Hargreaves
- Anorganische Chemie, Nachwuchsgruppe Hauptgruppenmetallchemie, Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35032 Marburg, Germany.
| |
Collapse
|
8
|
Roy MMD, Omaña AA, Wilson ASS, Hill MS, Aldridge S, Rivard E. Molecular Main Group Metal Hydrides. Chem Rev 2021; 121:12784-12965. [PMID: 34450005 DOI: 10.1021/acs.chemrev.1c00278] [Citation(s) in RCA: 122] [Impact Index Per Article: 40.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
This review serves to document advances in the synthesis, versatile bonding, and reactivity of molecular main group metal hydrides within Groups 1, 2, and 12-16. Particular attention will be given to the emerging use of said hydrides in the rapidly expanding field of Main Group element-mediated catalysis. While this review is comprehensive in nature, focus will be given to research appearing in the open literature since 2001.
Collapse
Affiliation(s)
- Matthew M D Roy
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Alvaro A Omaña
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| | - Andrew S S Wilson
- Department of Chemistry, University of Bath, Avon BA2 7AY, United Kingdom
| | - Michael S Hill
- Department of Chemistry, University of Bath, Avon BA2 7AY, United Kingdom
| | - Simon Aldridge
- Inorganic Chemistry Laboratory, Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QR, United Kingdom
| | - Eric Rivard
- Department of Chemistry, University of Alberta, 11227 Saskatchewan Drive, Edmonton, Alberta T6G 2G2, Canada
| |
Collapse
|
9
|
Le Coz E, Hammoud J, Roisnel T, Cordier M, Dorcet V, Kahlal S, Carpentier JF, Saillard JY, Sarazin Y. Bonding in Barium Boryloxides, Siloxides, Phenoxides and Silazides: A Comparison with the Lighter Alkaline Earths. Chemistry 2021; 27:11966-11982. [PMID: 34121256 DOI: 10.1002/chem.202101687] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Indexed: 11/11/2022]
Abstract
Barium complexes ligated by bulky boryloxides [OBR2 ]- (where R=CH(SiMe3 )2 , 2,4,6-i Pr3 -C6 H2 or 2,4,6-(CF3 )3 -C6 H2 ), siloxide [OSi(SiMe3 )3 ]- , and/or phenoxide [O-2,6-Ph2 -C6 H3 ]- , have been prepared. A diversity of coordination patterns is observed in the solid state for both homoleptic and heteroleptic complexes, with coordination numbers ranging between 2 and 4. The identity of the bridging ligand in heteroleptic dimers [Ba(μ2 -X1 )(X2 )]2 depends largely on the given pair of ligands X1 and X2 . Experimentally, the propensity to fill the bridging position increases according to [OB{CH(SiMe3 )2 }2 )]- <[N(SiMe3 )2 ]- <[OSi(SiMe3 )3 ]- <[O(2,6-Ph2 -C6 H3 )]- <[OB(2,4,6-i Pr3 -C6 H2 )2 ]- . This trend is the overall expression of 3 properties: steric constraints, electronic density and σ- and π-donating capability of the negatively charged atom, and ability to generate Ba ⋅ ⋅ ⋅ F, Ba ⋅ ⋅ ⋅ C(π) or Ba ⋅ ⋅ ⋅ H-C secondary interactions. The comparison of the structural motifs in the complexes [Ae{μ2 -N(SiMe3 )2 }(OB{CH(SiMe3 )2 }2 )]2 (Ae = Mg, Ca, Sr and Ba) suggest that these observations may be extended to all alkaline earths. DFT calculations highlight the largely prevailing ionic character of ligand-Ae bonding in all compounds. The ionic character of the Ae-ligand bond encourages bridging coordination, whereas the number of bridging ligands is controlled by steric factors. DFT computations also indicate that in [Ba(μ2 -X1 )(X2 )]2 heteroleptic dimers, ligand predilection for bridging vs. terminal positions is dictated by the ability to establish secondary interactions between the metals and the ligands.
Collapse
Affiliation(s)
- Erwann Le Coz
- Univ Rennes, CNRS ISCR, Institut des Sciences Chimiques de Rennes)-UMR 6226, 35000, Rennes, France
| | - Joanna Hammoud
- Univ Rennes, CNRS ISCR, Institut des Sciences Chimiques de Rennes)-UMR 6226, 35000, Rennes, France
| | - Thierry Roisnel
- Univ Rennes, CNRS ISCR, Institut des Sciences Chimiques de Rennes)-UMR 6226, 35000, Rennes, France
| | - Marie Cordier
- Univ Rennes, CNRS ISCR, Institut des Sciences Chimiques de Rennes)-UMR 6226, 35000, Rennes, France
| | - Vincent Dorcet
- Univ Rennes, CNRS ISCR, Institut des Sciences Chimiques de Rennes)-UMR 6226, 35000, Rennes, France
| | - Samia Kahlal
- Univ Rennes, CNRS ISCR, Institut des Sciences Chimiques de Rennes)-UMR 6226, 35000, Rennes, France
| | - Jean-François Carpentier
- Univ Rennes, CNRS ISCR, Institut des Sciences Chimiques de Rennes)-UMR 6226, 35000, Rennes, France
| | - Jean-Yves Saillard
- Univ Rennes, CNRS ISCR, Institut des Sciences Chimiques de Rennes)-UMR 6226, 35000, Rennes, France
| | - Yann Sarazin
- Univ Rennes, CNRS ISCR, Institut des Sciences Chimiques de Rennes)-UMR 6226, 35000, Rennes, France
| |
Collapse
|
10
|
Banerjee I, Panda TK. Recent developments in the reduction of unsaturated bonds by magnesium precursors. Appl Organomet Chem 2021. [DOI: 10.1002/aoc.6333] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Indrani Banerjee
- Department of Chemistry Indian Institute of Technology Hyderabad Sangareddy India
| | - Tarun K. Panda
- Department of Chemistry Indian Institute of Technology Hyderabad Sangareddy India
| |
Collapse
|
11
|
Chapple PM, Cartron J, Hamdoun G, Kahlal S, Cordier M, Oulyadi H, Carpentier JF, Saillard JY, Sarazin Y. Metal-metal bonded alkaline-earth distannyls. Chem Sci 2021; 12:7098-7114. [PMID: 34123338 PMCID: PMC8153243 DOI: 10.1039/d1sc00436k] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Accepted: 03/19/2021] [Indexed: 01/23/2023] Open
Abstract
The first families of alkaline-earth stannylides [Ae(SnPh3)2·(thf) x ] (Ae = Ca, x = 3, 1; Sr, x = 3, 2; Ba, x = 4, 3) and [Ae{Sn(SiMe3)3}2·(thf) x ] (Ae = Ca, x = 4, 4; Sr, x = 4, 5; Ba, x = 4, 6), where Ae is a large alkaline earth with direct Ae-Sn bonds, are presented. All complexes have been characterised by high-resolution solution NMR spectroscopy, including 119Sn NMR, and by X-ray diffraction crystallography. The molecular structures of [Ca(SnPh3)2·(thf)4] (1'), [Sr(SnPh3)2·(thf)4] (2'), [Ba(SnPh3)2·(thf)5] (3'), 4, 5 and [Ba{Sn(SiMe3)3}2·(thf)5] (6'), most of which crystallised as higher thf solvates than their parents 1-6, were established by XRD analysis; the experimentally determined Sn-Ae-Sn' angles lie in the range 158.10(3)-179.33(4)°. In a given series, the 119Sn NMR chemical shifts are slightly deshielded upon descending group 2 from Ca to Ba, while the silyl-substituted stannyls are much more shielded than the phenyl ones (δ 119Sn/ppm: 1', -133.4; 2', -123.6; 3', -95.5; 4, -856.8; 5, -848.2; 6', -792.7). The bonding and electronic properties of these complexes were also analysed by DFT calculations. The combined spectroscopic, crystallographic and computational analysis of these complexes provide some insight into the main features of these unique families of homoleptic complexes. A comprehensive DFT study (Wiberg bond index, QTAIM and energy decomposition analysis) points at a primarily ionic Ae-Sn bonding, with a small covalent contribution, in these series of complexes; the Sn-Ae-Sn' angle is associated with a flat energy potential surface around its minimum, consistent with the broad range of values determined by experimental and computational methods.
Collapse
Affiliation(s)
| | | | - Ghanem Hamdoun
- Normandie Université, UNIROUEN, INSA de Rouen, CNRS, Laboratoire COBRA (UMR 6014 & FR 3038) 76000 Rouen France
| | - Samia Kahlal
- Univ Rennes, CNRS, ISCR-UMR 6226 35000 Rennes France
| | - Marie Cordier
- Univ Rennes, CNRS, ISCR-UMR 6226 35000 Rennes France
| | - Hassan Oulyadi
- Normandie Université, UNIROUEN, INSA de Rouen, CNRS, Laboratoire COBRA (UMR 6014 & FR 3038) 76000 Rouen France
| | | | | | - Yann Sarazin
- Univ Rennes, CNRS, ISCR-UMR 6226 35000 Rennes France
| |
Collapse
|
12
|
Hammoud J, Abou-Khalil F, Roisnel T, Dorcet V, Bour C, Gandon V, Lebœuf D, Carpentier JF, Sarazin Y. Alkaline-earth complexes with macrocyclic-functionalised bis(phenolate)s and bis(fluoroalkoxide)s. Dalton Trans 2020; 49:13017-13028. [PMID: 32914818 DOI: 10.1039/d0dt02573a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The synthesis and structural features of several families of unsolvated molecular complexes of the heavy alkaline earths (Ae = calcium, strontium and barium) supported by bis(phenolate)s or bis(fluoroalkoxide)s are described. These dianionic, multidentate ligands are built around diaza-macrocycles that contain either five or six N- and O-heteroatoms. Several of these complexes have been characterised by X-ray diffraction crystallography. A list of comparative features was drawn upon close examination of the molecular structures of these complexes. It highlights the subtle influences of the identity of the central Ae metal, denticity and nature -fluoroalkoxide vs. phenolate- of the anionic tethers in the ligands. All complexes are seven- or eight-coordinate. It is observed in particular that a decrease of the number of heteroatoms in the macrocyclic backbone of the ligand will be compensated by the establishment of intramolecular AeF interactions (accounting for ca. 3.8-6.4% of the pertaining coordination spheres according to bond valence sum analysis), dimerisation of the complex, or, in one case, solvent (thf) retention. Attempts to gauge the Lewis acidity in these series of complexes were carried out by three independent methods (Childs, Gutmann-Beckett and global electrophilicity index). However, conflicting results were obtained and no clear trend can be delineated, even if on the whole, these measurements concur to suggest relatively low Lewis acidity.
Collapse
Affiliation(s)
- Joanna Hammoud
- Univ Rennes, CNRS, ISCR (Institut des Sciences Chimiques de Rennes) - UMR 6226, F-35000 Rennes, France.
| | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Magre M, Paffenholz E, Maity B, Cavallo L, Rueping M. Regiodivergent Hydroborative Ring Opening of Epoxides via Selective C-O Bond Activation. J Am Chem Soc 2020; 142:14286-14294. [PMID: 32658463 PMCID: PMC7458426 DOI: 10.1021/jacs.0c05917] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A magnesium-catalyzed regiodivergent C-O bond cleavage protocol is presented. Readily available magnesium catalysts achieve the selective hydroboration of a wide range of epoxides and oxetanes yielding secondary and tertiary alcohols in excellent yields and regioselectivities. Experimental mechanistic investigations and DFT calculations provide insight into the unexpected regiodivergence and explain the different mechanisms of the C-O bond activation and product formation.
Collapse
Affiliation(s)
- Marc Magre
- Institute of Organic Chemistry, RWTH Aachen, Landoltweg 1, Aachen 52074, Germany
| | - Eva Paffenholz
- Institute of Organic Chemistry, RWTH Aachen, Landoltweg 1, Aachen 52074, Germany
| | - Bholanath Maity
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Luigi Cavallo
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| | - Magnus Rueping
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| |
Collapse
|
14
|
Schuhknecht D, Spaniol TP, Yang Y, Maron L, Okuda J. Reactivity of a Molecular Calcium Hydride Cation ([CaH] +) Supported by an NNNN Macrocycle. Inorg Chem 2020; 59:9406-9415. [PMID: 32543844 DOI: 10.1021/acs.inorgchem.0c01289] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The hydride ligand in the cationic calcium hydride supported by a NNNN-type macrocycle, [(Me4TACD)2Ca2(μ-H)2(THF)][BAr4]2 (1; Me4TACD = 1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane; THF = tetrahydrofuran; BAr4 = B(C6H3-3,5-Me2)4), shows, in addition to its Brönsted basicity toward weak acids, a pronounced nucleophilicity resulting in nucleophilic substitution or insertion (addition) at a silicon or sp2 carbon center. Terminal acetylenes RC≡CH (R = SiMe3, cyclopropyl) as well as 1,4-diphenylbutadiene were deprotonated by 1 to give dinuclear complexes [(Me4TACD)2Ca2(μ-C≡CR)2][BAr4]2 (2a, R = SiMe3; 2b, R = cyclopropyl) and [(Me4TACD)2Ca2(μ2-η4-1,4-Ph2C4H2)][BAr4]2 (3) with H2 evolution. The addition reaction with BH3(THF) gave a tetrahydridoborate complex, [(Me4TACD)Ca(BH4)(THF)2][BAr4] (4), with κ2-H2BH2 coordination in the solid state, suggesting a pronounced Lewis acidic calcium center. The behavior resulting from both Lewis acidity and hydricity becomes apparent in the nucleophilic substitution of fluorobenzene by 1 to give benzene and the dimeric fluoride complex [(Me4TACD)2Ca2(μ-F)2(THF)][BAr4]2·2.5THF (5). Analogous nucleophilic substitution reaction is observed for heterofunctionalized organosilanes XSiR3 [X = I, N(SiHMe2)2, N3; R = Me3 or HMe2], which resulted in the formation of calcium complexes [(Me4TACD)Ca(X)(THF)n][BAr4] (6-8) containing an X ligand along with hydrosilane HSiR3. An insertion reaction by 1 was observed with CO2 and CO to give dinuclear formato complex [(Me4TACD)2Ca2(μ-OCHO)2][BAr4]2 (9) and cis-enediolato complex [(Me4TACD)2Ca2(μ-OCH═CHO)][BAr4]2·3.5THF (10), respectively. The latter is believed to have been formed as a result of the dimerization of an initially generated formyl or oxymethylene complex, [(Me4TACD)Ca(OCH)]+.
Collapse
Affiliation(s)
- Danny Schuhknecht
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52056 Aachen, Germany
| | - Thomas P Spaniol
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52056 Aachen, Germany
| | - Yan Yang
- CNRS, INSA, UPS, UMR 5215, LPCNO, Université de Toulouse, 135 avenue de Rangueil, 31077 Toulouse, France
| | - Laurent Maron
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52056 Aachen, Germany
| | - Jun Okuda
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52056 Aachen, Germany
| |
Collapse
|
15
|
Fener BE, Schüler P, Ueberschaar N, Bellstedt P, Görls H, Krieck S, Westerhausen M. Scope and Limitations of the s-Block Metal-Mediated Pudovik Reaction. Chemistry 2020; 26:7235-7243. [PMID: 32027050 PMCID: PMC7317549 DOI: 10.1002/chem.201905565] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Indexed: 11/29/2022]
Abstract
The hydrophosphorylation of phenylacetylene with di(aryl)phosphane oxides Ar2P(O)H (Pudovik reaction) yields E/Z‐isomer mixtures of phenylethenyl‐di(aryl)phosphane oxides (1). Alkali and alkaline‐earth metal di(aryl)phosphinites have been studied as catalysts for this reaction with increasing activity for the heavier s‐block metals. The Pudovik reaction can only be mediated for di(aryl)phosphane oxides whereas P‐bound alkyl and alcoholate substituents impede the P−H addition across alkynes. The demanding mesityl group favors the single‐hydrophosphorylated products 1‐Ar whereas smaller aryl substituents lead to the double‐hydrophosphorylated products 2‐Ar. Polar solvents are beneficial for an effective addition. Increasing concentration of the reactants and the catalyst accelerates the Pudovik reaction. Whereas Mes2P(O)H does not form the bis‐phosphorylated product 2‐Mes, activation of an ortho‐methyl group and cyclization occurs yielding 2‐benzyl‐1‐mesityl‐5,7‐dimethyl‐2,3‐dihydrophosphindole 1‐oxide (3).
Collapse
Affiliation(s)
- Benjamin E Fener
- Institute of Inorganic and Analytical Chemistry, Friedrich-Schiller-University Jena, Humboldtstr. 8, 07743, Jena, Germany
| | - Philipp Schüler
- Institute of Inorganic and Analytical Chemistry, Friedrich-Schiller-University Jena, Humboldtstr. 8, 07743, Jena, Germany
| | - Nico Ueberschaar
- Mass Spectrometry Platform, Friedrich Schiller University Jena, Humboldtstr. 8, 07743, Jena, Germany
| | - Peter Bellstedt
- NMR platform, Friedrich Schiller University Jena, Humboldtstr. 8, 07743, Jena, Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry, Friedrich-Schiller-University Jena, Humboldtstr. 8, 07743, Jena, Germany
| | - Sven Krieck
- Institute of Inorganic and Analytical Chemistry, Friedrich-Schiller-University Jena, Humboldtstr. 8, 07743, Jena, Germany
| | - Matthias Westerhausen
- Institute of Inorganic and Analytical Chemistry, Friedrich-Schiller-University Jena, Humboldtstr. 8, 07743, Jena, Germany
| |
Collapse
|
16
|
Magre M, Szewczyk M, Rueping M. N-Methylation and Trideuteromethylation of Amines via Magnesium-Catalyzed Reduction of Cyclic and Linear Carbamates. Org Lett 2020; 22:3209-3214. [PMID: 32216366 DOI: 10.1021/acs.orglett.0c00988] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A new reduction of carbamates to N-methyl amines is presented. The magnesium-catalyzed reduction reaction allows the conversion of cyclic and linear carbamates, including N-Boc protected amines, into the corresponding N-methyl amines and amino alcohols which are of significant interest due to their presence in many biologically active molecules. Furthermore, the reduction can be extended to the formation of N-trideuteromethyl labeled amines.
Collapse
Affiliation(s)
- Marc Magre
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Marcin Szewczyk
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Magnus Rueping
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany.,KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| |
Collapse
|
17
|
Chapple PM, Kahlal S, Cartron J, Roisnel T, Dorcet V, Cordier M, Saillard J, Carpentier J, Sarazin Y. Bis(imino)carbazolate: A Master Key for Barium Chemistry. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202001439] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
| | - Samia Kahlal
- Univ Rennes CNRS, ISCR-UMR 6226 35000 Rennes France
| | | | | | | | | | | | | | - Yann Sarazin
- Univ Rennes CNRS, ISCR-UMR 6226 35000 Rennes France
| |
Collapse
|
18
|
Chapple PM, Kahlal S, Cartron J, Roisnel T, Dorcet V, Cordier M, Saillard J, Carpentier J, Sarazin Y. Bis(imino)carbazolate: A Master Key for Barium Chemistry. Angew Chem Int Ed Engl 2020; 59:9120-9126. [DOI: 10.1002/anie.202001439] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Indexed: 01/14/2023]
Affiliation(s)
| | - Samia Kahlal
- Univ Rennes CNRS, ISCR-UMR 6226 35000 Rennes France
| | | | | | | | | | | | | | - Yann Sarazin
- Univ Rennes CNRS, ISCR-UMR 6226 35000 Rennes France
| |
Collapse
|
19
|
Le Coz E, Zhang Z, Roisnel T, Cavallo L, Falivene L, Carpentier J, Sarazin Y. Barium‐Catalysed Dehydrocoupling of Hydrosilanes and Borinic Acids: A Mechanistic Insight. Chemistry 2020; 26:3535-3544. [DOI: 10.1002/chem.201904933] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Indexed: 12/31/2022]
Affiliation(s)
- Erwann Le Coz
- CNRS, ISCR (Institut des Sciences Chimiques de Rennes)–UMR 6226Univ Rennes 35000 Rennes France
| | - Ziyun Zhang
- Physical Sciences and Engineering DivisionKaust Catalysis CenterKing Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia
| | - Thierry Roisnel
- CNRS, ISCR (Institut des Sciences Chimiques de Rennes)–UMR 6226Univ Rennes 35000 Rennes France
| | - Luigi Cavallo
- Physical Sciences and Engineering DivisionKaust Catalysis CenterKing Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia
| | - Laura Falivene
- Physical Sciences and Engineering DivisionKaust Catalysis CenterKing Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia
| | | | - Yann Sarazin
- CNRS, ISCR (Institut des Sciences Chimiques de Rennes)–UMR 6226Univ Rennes 35000 Rennes France
| |
Collapse
|
20
|
Birepinte M, Liautard V, Chabaud L, Pucheault M. Magnesium‐Catalyzed Tandem Dehydrogenation‐Dehydrocoupling: An Atom Economical Access to Alkynylboranes. Chemistry 2020; 26:3236-3240. [DOI: 10.1002/chem.201905772] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Indexed: 11/09/2022]
Affiliation(s)
- Mélodie Birepinte
- Institute of Molecular ScienceCNRS, Université de Bordeaux 351 Cours de la libération 33405 Talence Cedex France
| | - Virginie Liautard
- Institute of Molecular ScienceCNRS, Université de Bordeaux 351 Cours de la libération 33405 Talence Cedex France
| | - Laurent Chabaud
- Institute of Molecular ScienceCNRS, Université de Bordeaux 351 Cours de la libération 33405 Talence Cedex France
| | - Mathieu Pucheault
- Institute of Molecular ScienceCNRS, Université de Bordeaux 351 Cours de la libération 33405 Talence Cedex France
| |
Collapse
|
21
|
Schwamm RJ, Coles MP, Hill MS, Mahon MF, McMullin CL, Rajabi NA, Wilson ASS. A Stable Calcium Alumanyl. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 132:3956-3960. [PMID: 32313322 PMCID: PMC7159353 DOI: 10.1002/ange.201914986] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Indexed: 11/18/2022]
Abstract
A seven-membered N,N'-heterocyclic potassium alumanyl nucleophile is introduced and utilised in the metathetical synthesis of Mg-Al and Ca-Al bonded derivatives. Both species have been characterised by experimental and theoretical means, allowing a rationalisation of the greater reactivity of the heavier group 2 species implied by an initial assay of their reactivity.
Collapse
Affiliation(s)
| | - Martyn P. Coles
- School of Chemical and Physical SciencesVictoria University of WellingtonPO Box 600WellingtonNew Zealand
| | | | - Mary F. Mahon
- Department of ChemistryUniversity of BathBathBA2 7AYUK
| | | | | | | |
Collapse
|
22
|
Magre M, Szewczyk M, Rueping M. Magnesium-Catalyzed Stereoselective Hydrostannylation of Internal and Terminal Alkynes. Org Lett 2020; 22:1594-1598. [DOI: 10.1021/acs.orglett.0c00184] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Marc Magre
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Marcin Szewczyk
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Magnus Rueping
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| |
Collapse
|
23
|
Schwamm RJ, Coles MP, Hill MS, Mahon MF, McMullin CL, Rajabi NA, Wilson ASS. A Stable Calcium Alumanyl. Angew Chem Int Ed Engl 2020; 59:3928-3932. [PMID: 31830364 PMCID: PMC7159655 DOI: 10.1002/anie.201914986] [Citation(s) in RCA: 110] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2019] [Indexed: 12/02/2022]
Abstract
A seven‐membered N,N′‐heterocyclic potassium alumanyl nucleophile is introduced and utilised in the metathetical synthesis of Mg−Al and Ca−Al bonded derivatives. Both species have been characterised by experimental and theoretical means, allowing a rationalisation of the greater reactivity of the heavier group 2 species implied by an initial assay of their reactivity.
Collapse
Affiliation(s)
- Ryan J Schwamm
- Department of Chemistry, University of Bath, Bath, BA2 7AY, UK
| | - Martyn P Coles
- School of Chemical and Physical Sciences, Victoria University of Wellington, PO Box 600, Wellington, New Zealand
| | - Michael S Hill
- Department of Chemistry, University of Bath, Bath, BA2 7AY, UK
| | - Mary F Mahon
- Department of Chemistry, University of Bath, Bath, BA2 7AY, UK
| | | | - Nasir A Rajabi
- Department of Chemistry, University of Bath, Bath, BA2 7AY, UK
| | | |
Collapse
|
24
|
Shi X, Liu Z, Cheng J. Barium tetraalkylaluminate complexes supported by the super-bulky hydrotris(pyrazolyl)borate ligand. Dalton Trans 2019; 48:17919-17924. [PMID: 31782451 DOI: 10.1039/c9dt04182f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A heteroleptic barium aminobenzyl complex [(TpAd,iPr)Ba(o-CH2C6H4-NMe2)] (1) was obtained in excellent yield from a simple one-pot reaction. Treatment of [(TpAd,iPr)Ba(o-CH2C6H4-NMe2)] (1) with two equivalents of AlR3 (R = Me, Et) led to the formation of barium tetraalkylaluminate complexes [(TpAd,iPr)Ba(AlR4)]n (R = Me, n = 2, 2; R = Et, n = 1, 3) as dimers or monomers in the solid state. The TpAd,iPr ligand-free peralkylated barium complex [Ba(AlEt4)2]n was isolated by the addition of ten equivalents of AlEt3 under the same conditions. The donor-induced aluminate cleavage is not applicable when donor solvents are added to complexes 2 and 3. In the solution of complexes 2 and 3, the alkylaluminate moieties and TpAd,iPr ligands show a rapid fluxional behavior in [D8]toluene solution over the temperature range of -70 to 25 °C, without any significant decoalescence of the corresponding proton signals.
Collapse
Affiliation(s)
- Xianghui Shi
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, No. 5625, Renmin Street, Changchun 130022, China.
| | - Zhizhou Liu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, No. 5625, Renmin Street, Changchun 130022, China. and University of Science and Technology of China, Hefei, Anhui 230029, China
| | - Jianhua Cheng
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, No. 5625, Renmin Street, Changchun 130022, China. and University of Science and Technology of China, Hefei, Anhui 230029, China
| |
Collapse
|
25
|
Falconnet A, Magre M, Maity B, Cavallo L, Rueping M. Asymmetric Magnesium‐Catalyzed Hydroboration by Metal‐Ligand Cooperative Catalysis. Angew Chem Int Ed Engl 2019; 58:17567-17571. [DOI: 10.1002/anie.201908012] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Indexed: 12/20/2022]
Affiliation(s)
- Alban Falconnet
- Institute of Organic ChemistryRWTH Aachen Landoltweg 1 52074 Aachen Germany
| | - Marc Magre
- Institute of Organic ChemistryRWTH Aachen Landoltweg 1 52074 Aachen Germany
| | - Bholanath Maity
- KAUST Catalysis Center (KCC)King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia
| | - Luigi Cavallo
- KAUST Catalysis Center (KCC)King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia
| | - Magnus Rueping
- Institute of Organic ChemistryRWTH Aachen Landoltweg 1 52074 Aachen Germany
- KAUST Catalysis Center (KCC)King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia
| |
Collapse
|
26
|
Szewczyk M, Magre M, Zubar V, Rueping M. Reduction of Cyclic and Linear Organic Carbonates Using a Readily Available Magnesium Catalyst. ACS Catal 2019. [DOI: 10.1021/acscatal.9b04086] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Marcin Szewczyk
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, North Rhine-Westphalia, Germany
| | - Marc Magre
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, North Rhine-Westphalia, Germany
| | - Viktoriia Zubar
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, North Rhine-Westphalia, Germany
| | - Magnus Rueping
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, North Rhine-Westphalia, Germany
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), 23955-6900 Thuwal, Makkah Province, Saudi Arabia
| |
Collapse
|
27
|
Falconnet A, Magre M, Maity B, Cavallo L, Rueping M. Asymmetric Magnesium‐Catalyzed Hydroboration by Metal‐Ligand Cooperative Catalysis. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201908012] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Alban Falconnet
- Institute of Organic ChemistryRWTH Aachen Landoltweg 1 52074 Aachen Germany
| | - Marc Magre
- Institute of Organic ChemistryRWTH Aachen Landoltweg 1 52074 Aachen Germany
| | - Bholanath Maity
- KAUST Catalysis Center (KCC)King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia
| | - Luigi Cavallo
- KAUST Catalysis Center (KCC)King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia
| | - Magnus Rueping
- Institute of Organic ChemistryRWTH Aachen Landoltweg 1 52074 Aachen Germany
- KAUST Catalysis Center (KCC)King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia
| |
Collapse
|
28
|
Jang YK, Magre M, Rueping M. Chemoselective Luche-Type Reduction of α,β-Unsaturated Ketones by Magnesium Catalysis. Org Lett 2019; 21:8349-8352. [DOI: 10.1021/acs.orglett.9b03131] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yoon Kyung Jang
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Marc Magre
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Magnus Rueping
- Institute of Organic Chemistry, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal 23955-6900, Saudi Arabia
| |
Collapse
|
29
|
Affiliation(s)
- Lucia Garcia
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Mary F. Mahon
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| | - Michael S. Hill
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K
| |
Collapse
|
30
|
Roueindeji H, Ratsifitahina A, Roisnel T, Dorcet V, Kahlal S, Saillard J, Carpentier J, Sarazin Y. Metal⋅⋅⋅F−C Bonding in Low‐Coordinate Alkaline Earth Fluoroarylamides. Chemistry 2019; 25:8854-8864. [DOI: 10.1002/chem.201901262] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Indexed: 01/24/2023]
Affiliation(s)
| | | | | | | | - Samia Kahlal
- Univ Rennes, CNRSISCR-UMR 6226 35000 Rennes France
| | | | | | - Yann Sarazin
- Univ Rennes, CNRSISCR-UMR 6226 35000 Rennes France
| |
Collapse
|
31
|
Nguyen HN, Hultzsch KC. Rare-Earth-Metal-Catalyzed Kinetic Resolution of Chiral Aminoalkenes via Hydroamination: The Effect of the Silyl Substituent of the Binaphtholate Ligand on Resolution Efficiency. European J Org Chem 2019; 2019:2592-2601. [PMID: 31244549 PMCID: PMC6582503 DOI: 10.1002/ejoc.201900107] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Indexed: 01/11/2023]
Abstract
The kinetic resolution of α-substituted aminopentenes via intramolecular hydroamination was investigated using various 3,3'-silyl-substituted binaphtholate yttrium catalysts. High efficiencies in the kinetic resolution were observed for methyl-, benzyl-, and phenyl-substituted substrates utilizing the cyclohexyldiphenylsilyl-substituted catalyst 2c with resolution factors reaching as high as 90(5) for hex-5-en-2-amine (3a). Kinetic analysis of the enantioenriched substrates with the matching and mismatching catalyst revealed that the efficiency of catalyst 2c benefits significantly from a favorable Curtin-Hammett pre-equilibrium and by a large kfast/kslow ratio. Other binaphtholate catalysts were less efficient due to a less favorable Curtin-Hammett pre-equilibrium, which often favored the mismatching substrate-catalyst combination. Cyclization of the matched substrate proceeds generally with large trans-selectivity, whereas the trans/cis-ratio for mismatched substrates is significantly diminished, favoring the cis-cyclization product isomer in some instances.
Collapse
Affiliation(s)
- Hiep N Nguyen
- Department of Chemistry and Chemical Biology Rutgers, The State University of New Jersey 610 Taylor Road 8087 Piscataway, New Jersey 08854- USA
| | - Kai C Hultzsch
- Universität Wien Fakultät für Chemie Institut für Chemische Katalyse Währinger Straße 38 1090 Wien Austria
| |
Collapse
|
32
|
Magre M, Maity B, Falconnet A, Cavallo L, Rueping M. Magnesium‐Catalyzed Hydroboration of Terminal and Internal Alkynes. Angew Chem Int Ed Engl 2019. [DOI: 10.1002/ange.201902188] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Marc Magre
- Institute of Organic ChemistryRWTH Aachen Landoltweg 1 52074 Aachen Germany
| | - Bholanath Maity
- KAUST Catalysis Center (KCC)King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia
| | - Alban Falconnet
- Institute of Organic ChemistryRWTH Aachen Landoltweg 1 52074 Aachen Germany
| | - Luigi Cavallo
- KAUST Catalysis Center (KCC)King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia
| | - Magnus Rueping
- Institute of Organic ChemistryRWTH Aachen Landoltweg 1 52074 Aachen Germany
- KAUST Catalysis Center (KCC)King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia
| |
Collapse
|
33
|
Magre M, Maity B, Falconnet A, Cavallo L, Rueping M. Magnesium-Catalyzed Hydroboration of Terminal and Internal Alkynes. Angew Chem Int Ed Engl 2019; 58:7025-7029. [PMID: 30977970 DOI: 10.1002/anie.201902188] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Indexed: 11/10/2022]
Abstract
A magnesium-catalyzed hydroboration of alkynes providing good yields and selectivities for a wide range of terminal and symmetrical and unsymmetrical internal alkynes has been developed. The compatibility with many functional groups makes this magnesium catalyzed procedure attractive for late stage functionalization. Experimental mechanistic investigations and DFT calculations reveal insights into the reaction mechanism of the magnesium catalyzed protocol.
Collapse
Affiliation(s)
- Marc Magre
- Institute of Organic Chemistry, RWTH Aachen, Landoltweg 1, 52074, Aachen, Germany
| | - Bholanath Maity
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Alban Falconnet
- Institute of Organic Chemistry, RWTH Aachen, Landoltweg 1, 52074, Aachen, Germany
| | - Luigi Cavallo
- KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| | - Magnus Rueping
- Institute of Organic Chemistry, RWTH Aachen, Landoltweg 1, 52074, Aachen, Germany.,KAUST Catalysis Center (KCC), King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia
| |
Collapse
|
34
|
de Bruin‐Dickason CN, Deacon GB, Jones C, Junk PC, Wiecko M. Functionalised Alkaline Earth Iodides from Grignard Synthons “PhAeI(thf)
n
” (Ae = Mg‐Ba). Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201801489] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Glen B. Deacon
- School of Chemistry Monash University Clayton Vic. 3800 Australia
| | - Cameron Jones
- School of Chemistry Monash University Clayton Vic. 3800 Australia
| | - Peter C. Junk
- College of Science & Engineering James Cook University Townsville, Qld., 4811 Australia
| | - Michal Wiecko
- School of Chemistry Monash University Clayton Vic. 3800 Australia
| |
Collapse
|
35
|
Le Coz E, Roueindeji H, Roisnel T, Dorcet V, Carpentier JF, Sarazin Y. Barium complexes with crown-ether-functionalised amidinate and iminoanilide ligands for the hydrophosphination of vinylarenes. Dalton Trans 2019; 48:9173-9180. [DOI: 10.1039/c9dt01512d] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Two barium-amide complexes bearing crown-ether-functionalised amidinate and iminoanilide ligands that act as competent precatalysts for the intermolecular hydrophosphination of vinylarenes are presented.
Collapse
Affiliation(s)
- Erwann Le Coz
- Univ Rennes
- CNRS
- ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226
- F-35000 Rennes
- France
| | - Hanieh Roueindeji
- Univ Rennes
- CNRS
- ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226
- F-35000 Rennes
- France
| | - Thierry Roisnel
- Univ Rennes
- CNRS
- ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226
- F-35000 Rennes
- France
| | - Vincent Dorcet
- Univ Rennes
- CNRS
- ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226
- F-35000 Rennes
- France
| | | | - Yann Sarazin
- Univ Rennes
- CNRS
- ISCR (Institut des Sciences Chimiques de Rennes) – UMR 6226
- F-35000 Rennes
- France
| |
Collapse
|
36
|
Krieck S, Kalden D, Oberheide A, Seyfarth L, Arndt HD, Görls H, Westerhausen M. Synthesis and catalytic activity of tridentate N-(2-pyridylethyl)-substituted bulky amidinates of calcium and strontium. Dalton Trans 2019; 48:2479-2490. [DOI: 10.1039/c8dt04905j] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sterically protected tridentate amidinates of calcium have been prepared to study the intramolecular hydroamination of an aminoalkene.
Collapse
Affiliation(s)
- Sven Krieck
- Institute of Inorganic and Analytical Chemistry
- Friedrich Schiller University
- 07743 Jena
- Germany
| | - Diana Kalden
- Institute of Inorganic and Analytical Chemistry
- Friedrich Schiller University
- 07743 Jena
- Germany
| | - Ansgar Oberheide
- Institute of Organic Chemistry and Macromolecular Chemistry
- Friedrich Schiller University
- 07743 Jena
- Germany
| | - Lydia Seyfarth
- Institute of Organic Chemistry and Macromolecular Chemistry
- Friedrich Schiller University
- 07743 Jena
- Germany
| | - Hans-Dieter Arndt
- Institute of Organic Chemistry and Macromolecular Chemistry
- Friedrich Schiller University
- 07743 Jena
- Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry
- Friedrich Schiller University
- 07743 Jena
- Germany
| | - Matthias Westerhausen
- Institute of Inorganic and Analytical Chemistry
- Friedrich Schiller University
- 07743 Jena
- Germany
| |
Collapse
|
37
|
Krieck S, Schüler P, Görls H, Westerhausen M. Alkaline-Earth Metal Bis[bis(trimethylsilyl)amide] Complexes with Weakly Coordinating 2,2,5,5-Tetramethyltetrahydrofuran Ligands. Inorg Chem 2018; 57:13937-13943. [DOI: 10.1021/acs.inorgchem.8b02469] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Sven Krieck
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, D-07743 Jena, Germany
| | - Philipp Schüler
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, D-07743 Jena, Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, D-07743 Jena, Germany
| | - Matthias Westerhausen
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, D-07743 Jena, Germany
| |
Collapse
|
38
|
Nguyen HN, Lee H, Audörsch S, Reznichenko AL, Nawara-Hultzsch AJ, Schmidt B, Hultzsch KC. Asymmetric Intra- and Intermolecular Hydroamination Catalyzed by 3,3′-Bis(trisarylsilyl)- and 3,3′-Bis(arylalkylsilyl)-Substituted Binaphtholate Rare-Earth-Metal Complexes. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00510] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hiep N. Nguyen
- Department of Chemistry & Chemical Biology, Rutgers, The State University of New Jersey, 610 Taylor Road, Piscataway, New Jersey 08854-8087, United States
| | - Hyeunjoo Lee
- Department of Chemistry & Chemical Biology, Rutgers, The State University of New Jersey, 610 Taylor Road, Piscataway, New Jersey 08854-8087, United States
| | - Stephan Audörsch
- Institut für Chemie, Organische Synthesechemie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Golm, Germany
| | - Alexander L. Reznichenko
- Department of Chemistry & Chemical Biology, Rutgers, The State University of New Jersey, 610 Taylor Road, Piscataway, New Jersey 08854-8087, United States
| | - Agnieszka J. Nawara-Hultzsch
- University of Vienna, Faculty of Chemistry, Institute of Chemical Catalysis, Währinger Strasse 38, 1090 Vienna, Austria
| | - Bernd Schmidt
- Institut für Chemie, Organische Synthesechemie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Golm, Germany
| | - Kai C. Hultzsch
- Department of Chemistry & Chemical Biology, Rutgers, The State University of New Jersey, 610 Taylor Road, Piscataway, New Jersey 08854-8087, United States
- University of Vienna, Faculty of Chemistry, Institute of Chemical Catalysis, Währinger Strasse 38, 1090 Vienna, Austria
| |
Collapse
|
39
|
Affiliation(s)
- Jürgen Pahl
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| | - Alexander Friedrich
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| | - Holger Elsen
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 1, 91058 Erlangen, Germany
| |
Collapse
|
40
|
Härling SM, Fener BE, Krieck S, Görls H, Westerhausen M. Potassium Dimesitylphosphinite Catalyzed Intermolecular Hydrophosphorylation of Alkynes. Organometallics 2018. [DOI: 10.1021/acs.organomet.8b00368] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Stephan M. Härling
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, D-07743 Jena, Germany
| | - Benjamin E. Fener
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, D-07743 Jena, Germany
| | - Sven Krieck
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, D-07743 Jena, Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, D-07743 Jena, Germany
| | - Matthias Westerhausen
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, D-07743 Jena, Germany
| |
Collapse
|
41
|
Mukherjee D, Schuhknecht D, Okuda J. Hydrido Complexes of Calcium: A New Family of Molecular Alkaline-Earth-Metal Compounds. Angew Chem Int Ed Engl 2018; 57:9590-9602. [DOI: 10.1002/anie.201801869] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Indexed: 12/16/2022]
Affiliation(s)
- Debabrata Mukherjee
- Institute of Inorganic Chemistry; RWTH Aachen University; Landoltweg 1 52056 Aachen Germany
| | - Danny Schuhknecht
- Institute of Inorganic Chemistry; RWTH Aachen University; Landoltweg 1 52056 Aachen Germany
| | - Jun Okuda
- Institute of Inorganic Chemistry; RWTH Aachen University; Landoltweg 1 52056 Aachen Germany
| |
Collapse
|
42
|
Mukherjee D, Schuhknecht D, Okuda J. Hydrido-Komplexe des Calciums: eine neue Familie molekularer Erdalkalimetall-Verbindungen. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201801869] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Debabrata Mukherjee
- Institut für Anorganische Chemie; RWTH Aachen; Landoltweg 1 52056 Aachen Deutschland
| | - Danny Schuhknecht
- Institut für Anorganische Chemie; RWTH Aachen; Landoltweg 1 52056 Aachen Deutschland
| | - Jun Okuda
- Institut für Anorganische Chemie; RWTH Aachen; Landoltweg 1 52056 Aachen Deutschland
| |
Collapse
|
43
|
Pahl J, Brand S, Elsen H, Harder S. Highly Lewis acidic cationic alkaline earth metal complexes. Chem Commun (Camb) 2018; 54:8685-8688. [PMID: 29892727 DOI: 10.1039/c8cc04083d] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Cationic Lewis base-free β-diketiminate (BDI) complexes of Mg and Ca have been isolated as their B(C6F5)4- salts. The cation (BDI)Mg+ shows an extraordinarily strong Lewis acidity that can compete with strong Lewis acids like B(C6F5)3 and (BDI)AlMe+. Its highly electrophilic nature is exemplified by isolation of an 3-hexyne adduct.
Collapse
Affiliation(s)
- Jürgen Pahl
- Inorganic and Organometallic Chemistry, University Erlangen-Nürnberg, Egerlandstrasse 1, 91058 Erlangen, Germany.
| | - Steffen Brand
- Inorganic and Organometallic Chemistry, University Erlangen-Nürnberg, Egerlandstrasse 1, 91058 Erlangen, Germany.
| | - Holger Elsen
- Inorganic and Organometallic Chemistry, University Erlangen-Nürnberg, Egerlandstrasse 1, 91058 Erlangen, Germany.
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry, University Erlangen-Nürnberg, Egerlandstrasse 1, 91058 Erlangen, Germany.
| |
Collapse
|
44
|
Freitag B, Stegner P, Thum K, Fischer CA, Harder S. Tetranuclear Strontium and Barium Siloxide/Amide Clusters in Metal-Ligand Cooperative Catalysis. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800231] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Benjamin Freitag
- Inorganic and Organometallic Chemistry; University of Erlangen-Nürnberg; Egerlandstrasse 1 91058 Erlangen Germany
| | - Phillip Stegner
- Inorganic and Organometallic Chemistry; University of Erlangen-Nürnberg; Egerlandstrasse 1 91058 Erlangen Germany
| | - Katharina Thum
- Inorganic and Organometallic Chemistry; University of Erlangen-Nürnberg; Egerlandstrasse 1 91058 Erlangen Germany
| | - Christian A. Fischer
- Inorganic and Organometallic Chemistry; University of Erlangen-Nürnberg; Egerlandstrasse 1 91058 Erlangen Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry; University of Erlangen-Nürnberg; Egerlandstrasse 1 91058 Erlangen Germany
| |
Collapse
|
45
|
|
46
|
Ziemann S, Krieck S, Görls H, Westerhausen M. 1,2-Bis(anilido)ethane Complexes of Calcium and Potassium: Synthesis, Structures, and Catalytic Activity. Organometallics 2018. [DOI: 10.1021/acs.organomet.7b00890] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Steffen Ziemann
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, D-07743 Jena, Germany
| | - Sven Krieck
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, D-07743 Jena, Germany
| | - Helmar Görls
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, D-07743 Jena, Germany
| | - Matthias Westerhausen
- Institute of Inorganic and Analytical Chemistry, Friedrich Schiller University Jena, Humboldtstraße 8, D-07743 Jena, Germany
| |
Collapse
|
47
|
Leng JD, Goodwin CAP, Vitorica-Yrezabal IJ, Mills DP. Salt metathesis routes to homoleptic near-linear Mg(ii) and Ca(ii) bulky bis(silyl)amide complexes. Dalton Trans 2018; 47:12526-12533. [DOI: 10.1039/c8dt00802g] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
A series of bulky bis(silyl)amide ligands have been utilised to stabilise rare examples of formally 2-coordinate linear or near-linear Mg and Ca complexes.
Collapse
Affiliation(s)
- Ji-Dong Leng
- Guangzhou Key Laboratory for Environmentally Functional Materials and Technology
- School of Chemistry and Chemical Engineering
- Guangzhou University
- Guangzhou Higher Education Mega Center
- Guangzhou
| | | | | | - David P. Mills
- School of Chemistry
- The University of Manchester
- Manchester
- UK
| |
Collapse
|
48
|
Mukherjee D, Okuda J. Molecular Magnesium Hydrides. Angew Chem Int Ed Engl 2017; 57:1458-1473. [DOI: 10.1002/anie.201708592] [Citation(s) in RCA: 69] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Indexed: 11/12/2022]
Affiliation(s)
- Debabrata Mukherjee
- Institute of Inorganic Chemistry; RWTH Aachen University; Landoltweg 1 52056 Aachen Germany
| | - Jun Okuda
- Institute of Inorganic Chemistry; RWTH Aachen University; Landoltweg 1 52056 Aachen Germany
| |
Collapse
|
49
|
Affiliation(s)
- Debabrata Mukherjee
- Institut für Anorganische Chemie; RWTH Aachen; Landoltweg 1 52056 Aachen Deutschland
| | - Jun Okuda
- Institut für Anorganische Chemie; RWTH Aachen; Landoltweg 1 52056 Aachen Deutschland
| |
Collapse
|
50
|
Rauch M, Ruccolo S, Parkin G. Synthesis, Structure, and Reactivity of a Terminal Magnesium Hydride Compound with a Carbatrane Motif, [Tism PriBenz]MgH: A Multifunctional Catalyst for Hydrosilylation and Hydroboration. J Am Chem Soc 2017; 139:13264-13267. [PMID: 28901762 DOI: 10.1021/jacs.7b06719] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The tris[(1-isopropylbenzimidazol-2-yl)dimethylsilyl)]methyl ligand, [TismPriBenz], has been employed to form the magnesium carbatrane compound, [TismPriBenz]MgH, which possesses a terminal hydride ligand. Specifically, [TismPriBenz]MgH is obtained via the reaction of [TismPriBenz]MgMe with PhSiH3. The reactivity of [TismPriBenz]MgMe and [TismPriBenz]MgH allows access to a variety of other structurally characterized carbatrane derivatives, including [TismPriBenz]MgX [X = F, Cl, Br, I, SH, N(H)Ph, CH(Me)Ph, O2CMe, S2CMe]. In addition, [TismPriBenz]MgH is a catalyst for (i) hydrosilylation and hydroboration of styrene to afford the Markovnikov products, Ph(Me)C(H)SiH2Ph and Ph(Me)C(H)Bpin, and (ii) hydroboration of carbodiimides and pyridine to form N-boryl formamidines and N-boryl 1,4- and 1,2-dihydropyridines, respectively.
Collapse
Affiliation(s)
- Michael Rauch
- Department of Chemistry, Columbia University , New York, New York 10027, United States
| | - Serge Ruccolo
- Department of Chemistry, Columbia University , New York, New York 10027, United States
| | - Gerard Parkin
- Department of Chemistry, Columbia University , New York, New York 10027, United States
| |
Collapse
|