- Iron-Catalyzed Cross-Coupling of Alkynyl and Styrenyl Chlorides with Alkyl Grignard Reagents in Batch and Flow
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Transition-metal-catalyzed cross-coupling chemistry can be regarded as one of the most powerful protocols to construct carbon–carbon bonds. While the field is still dominated by palladium catalysis, there is an increasing interest to develop protocols that utilize cheaper and more sustainable metal sources. Herein, we report a selective, practical, and fast iron-based cross-coupling reaction that enables the formation of Csp?Csp3 and Csp2?Csp3 bonds. In a telescoped flow process, the reaction can be combined with the Grignard reagent synthesis. Moreover, flow allows the use of a supporting ligand to be avoided without eroding the reaction selectivity.
- Deng, Yuchao,Wei, Xiao-Jing,Wang, Xiao,Sun, Yuhan,No?l, Timothy
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supporting information
p. 14532 - 14535
(2019/11/21)
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- Chromium(II)-Catalyzed Diastereoselective and Chemoselective Csp2-Csp3 Cross-Couplings Using Organomagnesium Reagents
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A simple protocol for performing chromium-catalyzed highly diastereoselective alkylations of arylmagnesium halides with cyclohexyl iodides at ambient temperature has been developed. Furthermore, this ligand-free CrCl2 enables efficient electrophilic alkenylations of primary, secondary, and tetiary alkylmagnesium halides with readily available alkenyl acetates. Moreover, this chemoselective C-C coupling reaction with stereodefined alkenyl acetates proceeds in a stereoretentive fashion. A wide range of functional groups on alkyl iodides and alkenyl acetates are well tolerated, thus furnishing functionalized Csp2-Csp3 coupling products in good yields and high diastereoselectivity. Detailed mechanistic studies suggest that the in situ generated low-valent chromium(I) species might be the active catalyst for these Csp2-Csp3 cross-couplings.
- Li, Jie,Ren, Qianyi,Cheng, Xinyi,Karaghiosoff, Konstantin,Knochel, Paul
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supporting information
p. 18127 - 18135
(2019/11/19)
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- DIALKYL(2-ALKOXY-6-AMINOPHENYL)PHOSPHINE, THE PREPARATION METHOD AND USE THEREOF
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The present invention relates to the compound of dialkyl(2-alkoxy-6-aminophenyl)phosphine and the preparation method thereof and the application in the palladium catalyzed coupling reactions of aryl chloride and ketone. The dialkyl(2-alkoxy-6-aminophenyl)phosphine of the present invention could coordinate with the palladium catalyst to highly selectively activate the inert carbon-chlorine bond, and to catalyze direct arylation reaction in the α-position of ketones to produce corresponding coupling compounds. The preparation method of the present invention is a simple one-step method which produces the air-stable dialkyl(2-alkoxy-6-aminophenyl)phosphine. Compared with the synthetic routes of ligands to be used in the activation of carbon-chlorine bonds in the prior arts, the preparation method of the present invention has the advantages of short route and easy operation.
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Paragraph 0033
(2014/10/29)
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- METHOD FOR PREPARING DI-ORGANO-DIALKOXYSILANES
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The present invention relates to a method for preparing di-organo-dialkoxysilanes, in particular di-organo-dialkoxysilanes wherein one or both of the organic substituents are bulky. The method comprises reacting a tetraalkoxysilane compound with a first Grignard reagent to form a mono-organo-tri-alkoxysilane compound, which is then reacted with a chlorinating agent to form a chlorinated mono-organo-di-alkoxysilane which is then reacted with a second Grignard reagent to form the di-organo-di-alkoxysilane compound.
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Paragraph 0060
(2013/07/19)
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- STRUCTURE AND METHOD FOR SYNTHESIZING AND USING DIALKYL(2,4,6- OR 2,6-ALKOXYPHENYL)PHOSPHINE AND ITS TETRAFLUOROBORATE
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The current invention relates to the structure, synthesis of dialkyl(2,4,6- or 2,6-alkoxyphenyl)phosphine or its tetrafluoroborate, as well as its applications in the palladium catalyzed carbon-chlorine bond activation for Suzuki coupling reactions and carbon-nitrogen bond formation reactions. The dialkyl(2,4,6- or 2,6-alkoxyphenyl)phosphine or its tetrafluoroborate could coordinate with the palladium catalyst to activate the inert carbon-chlorine bond highly selectively and catalyze Suzuki coupling reaction with arylboronic acid or carbon-nitrogen bond formation reaction with organic amines. The current invention uses only one step to synthesize dialkyl(2,4,6- or 2,6-alkoxyphenyl)phosphine and its tetrafluoroborate is stable in the air. Compared with known synthetic routes of ligands used in activating carbon-chlorine bonds, the method of current invention is short, easy to operate. Moreover, with this type of ligands, the Suzuki coupling products of optically active chlorolactones and arylboronic acids would maintain their configuration and optical purity.
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Page/Page column 4-5
(2012/08/08)
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- PROCESS FOR PRODUCING PHOSPHONIUM BORATE COMPOUND, NOVEL PHOSPHONIUM BORATE COMPOUND, AND METHOD OF USING THE SAME
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The invention relates to a phosphonium borate compound represented by Formula (I) (hereinafter, the compound (I)). The invention has objects of providing (A) a novel process whereby the compound is produced safely on an industrial scale, by simple reaction operations and in a high yield; (B) a novel compound that is easily handled; and (C) novel use as catalyst. ????????Formula (I) : (R1)(R2)(R3)PH·BAr4?????(I) wherein R1, R2, R3 and Ar are as defined in the specification. The process (A) includes reacting a phosphine with a) HCl or b) H2SO4 to produce a) a hydrochloride or b) a sulfate; and reacting the salt with a tetraarylborate compound. The compound (B) has for example a secondary or tertiary alkyl group as R1 and is easily handled in air without special attention. The use (C) is characterized in that the compound (I) is used instead of an unstable phosphine compound of a transition metal complex catalyst for catalyzing C-C bond, C-N bond and C-O bond forming reactions and the compound produces an effect that is equal to that achieved by the transition metal complex catalyst.
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Page/Page column 69-70
(2008/06/13)
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- Production processes for triorganomonoalkoxysilanes and triorganomonochlorosilanes
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A silane containing a bulky hydrocarbon group or groups R therein and having the formula (III) [in-line-formulae]R3-(x+y)(R1)x(R2)ySi(OR3) [/in-line-formulae] can be produced by reacting a silane of the formula (I) [in-line-formulae](R1)x(R2) ySiCl3-(x+y)(OR3) [/in-line-formulae] with a Grignard reagent of the formula (II) [in-line-formulae]RMgX [/in-line-formulae] Further, a tri-organo-chlorosilane of the formula (XIIa) [in-line-formulae](R1)(R2)(R3)SiCl [/in-line-formulae] can be produced by reacting a tri-organo-silane of the formula (XIa) [in-line-formulae](R1)(R2)(R3)SiZ1 [/in-line-formulae] with hydrochloric acid. Furthermore, a tri-organo-monoalkoxysilane of the formula (XXIII) [in-line-formulae]R3-(x+y)(R1)x(R2)ySi(OR3) [/in-line-formulae] can be produced when a silane of the formula (XXI) [in-line-formulae](R1)x(R2)ySiCl4-(x+y) [/in-line-formulae] is reacted with a Grignard reagent of the formula (XXII) [in-line-formulae]RMgX [/in-line-formulae] with addition of and reaction with an alcohol or an epoxy compound during the reaction.
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Page/Page column 22; 24; 26; 28; 29
(2008/06/13)
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- Sterically crowded diphosphinomethane ligands: Molecular structures, UV-photoelectron spectroscopy and a convenient general synthesis of tBu2PCH2PtBu2 and related species
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A series of highly crowded symmetric and unsymmetric diphosphinomethanes R2PCH2PR′2, important ligands in transition metal chemistry and catalysis, namely tBu2PCH2ptBu2 (dtbpm, 11), Cy2PCH2PCy2 (dcpm, 2), tBu2PCH2PCy2 (ctbpm, 3), tBu2PCH2PiPr2 (iptbpm, 4) and tBu2PCH2PPh2 (ptbpm, 5), has been prepared in high yields, using a general and convenient route, which is described in detail for 1. Other than 4, which is a colourless liquid, these compounds are crystalline solids at room temperature. Their molecular structures have been determined by single crystal X-ray diffraction, along with that of the higher homologue of 1, tBu2CH2CH2tBu 2 (dtbpe, 6). The solid-state structures of the dioxide of 1, tBu2P(O)CH2P(O)tBu2 (7), and of two phosphonium cations derived from 1, protonated [tBu2P(H)CH2PtBu2] + (8+) and the chlorophosphonium ion [tBu2P(Cl)CH2PtBu2] + (9+), are also described and show a distinct structural influence of the tetracoordinate P centres. The gas phase UV-photoelectron spectra of the diphosphines 1-6 have been measured. Their first two ionisation potentials are found to be nearly degenerate and all are in the low energy range from 7.5 to 7.8 eV. Comparison with related mono- and bidentate phosphines demonstrates that 1-6 are excellent σ-donors towards metals, in accord with their known coordination chemistry. Molecular geometries and electronic structures of the diphosphine systems have been studied by quantum chemical calculations and are compared to experiment. Unlike standard semiempirical methods (AM1, PM3, MNDO), which give rather poor minimum structures and seem inadequate for such sterically crowded systems, ab initio calculations (RHF/6-31G**) predict molecular geometries with reasonable accuracy and reflect the observed trends in experimental ionisation potentials.
- Eisentraeger, Frank,Goethlich, Alexander,Gruber, Irene,Heiss, Helmut,Kiener, Christoph A.,Krueger, Carl,Notheis, J. Ulrich,Rominger, Frank,Scherhag, Gunter,Schultz, Madeleine,Straub, Bernd F.,Volland, Martin A. O.,Hofmann, Peter
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p. 540 - 550
(2007/10/03)
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- Process for preparation of asymmetric triorganotin halide
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A process for the preparation of an asymmetric triorganotin halide which is represented by the general formula [III] STR1 wherein R represents alkyl or phenyl, R* represents cyclohexyl or neophyl, and X represents a chlorine or bromine atom, which comprises reacting in the presence or absence of an inert organic solvent an asymmetric tetraorganotin compound of the general formula [I] STR2 with a tin (IV) halide of the general formula [II] in approximately equimolar amounts to yield a reaction mixture including compounds of the general formula of [III] and [IV] STR3 and subsequently, without the isolation of the asymmetric triorganotin halide [III], reacting the reaction mixture with substantially twice the molar amount, based on monoorganotin trihalide [IV], of an ether solution of organomagnesium halide of the general formula of [V]
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