- Palladium-catalyzed cross-coupling of benzyltitanium(IV) reagents with aryl fluorides
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The first palladium-catalyzed cross-coupling between benzyltitanium(IV) reagents with aryl fluorides is reported. A variety of diarylmethanes can be prepared in good to excellent yields by the catalyst system of PdCl2(dppf)2 associated with 1-[2-(di-tert-butylphosphanyl)phenyl]-4-methoxypiperidine. This reaction offered a highly efficient approach to diarylmethanes that are commonly found in life-changing drug molecules. Graphical abstract: [Figure not available: see fulltext.]
- Li, Yan
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- Method for Catalytic Enantioselective Alkylation of Aldehydes Using Grignard Reagents as Alkyl Sources
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Alkyltitanium reagents, generated in situ from Grignard reagents and ClTi(OiPr)3, can be employed without further manipulation in the enantioselective alkylation of aldehyde by the catalysis of a chiral titanium complex derived from DTBP-H8-BINOL. The reaction is performed with good stoichiometry [1.5 equiv each of Grignard reagents and ClTi(OiPr)3] at a low catalyst loading (2 mol %), affording a variety of chiral secondary alcohols in high enantioselectivity and yields and, hence, realizing an asymmetric version of the Grignard reaction in an indirect manner.
- Tanaka, Kento,Tomihama, Munehisa,Yamamoto, Koji,Matsubara, Naoki,Harada, Toshiro
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p. 6127 - 6132
(2018/05/23)
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- Catalytic Enantioselective Arylation and Heteroarylation of Ketones with Organotitanium Reagents Generated In Situ
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A practical and useful, catalytic enantioselective method has been developed for the synthesis of tertiary diaryl and aryl heteroaryl carbinols starting from commercially available aromatic ketones and aryl or heteroaryl bromides. In this method, organotitanium reagents are generated in situ from the bromides by lithiation with nBuLi followed by transmetallation of the resulting organolithiums with ClTi(OiPr)3. Treatment of the ketones with the titanium reagents in the presence of (R)-3-(3,5-bistrifluoromehthylphenyl)-1,1′-bi-2-naphthol (BTFP-BINOL) affords the corresponding tertiary alcohols in high enantioselectivities and yields. The reaction can also start with furan and 2-thienyllithium. The method is operationally simple and can be conducted on a 10-mmol scale without any difficulties.
- Matsuda, Atsushi,Ushimaru, Tomoya,Kobayashi, Yusuke,Harada, Toshiro
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supporting information
p. 8605 - 8609
(2017/06/30)
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- GROUP 4 METAL COMPLEX, PRODUCTION METHOD THEREOF, PREPARATION METHOD OF GROUP 4 METAL-CONTAINING THIN FILM
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PROBLEM TO BE SOLVED: To provide a group 4 metal complex having excellent thermal stability and proper vapor pressure and suitable as a material for preparing a group 4 metal-containing thin film. SOLUTION: There is provided the group 4 metal complex represented by the general formula (1), where M represents a group 4 metal atom, R1, R2, R3 and R4 each represent independently a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, R5, R6 and R7 each represent independently an alkyl group having 1 to 8 carbon atoms, R8, R9 and R10 each represent independently an alkyl group having 1 to 6 carbon atoms or a di (alkyl having 1 to 3 carbon atoms) amino group. SELECTED DRAWING: None COPYRIGHT: (C)2016,JPO&INPIT
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Paragraph 0076; 0079
(2018/10/03)
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- Heating under high-frequency inductive conditions: Application to the continuous synthesis of the neurolepticum olanzapine (Zyprexa)
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Hot chemistry! High-frequency inductive heating and flow chemistry are an ideal match for high-temperature synthesis. This is demonstrated in the multistep flow synthesis of the neurolepticum olanzapine (Zyprexa) that included three reactions with inductive heating and two purification steps conducted as continuous processes. Copyright
- Hartwig, Jan,Ceylan, Sascha,Kupracz, Lukas,Coutable, Ludovic,Kirschning, Andreas
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supporting information
p. 9813 - 9817
(2013/09/23)
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- PROCESS FOR PRODUCING OPTICALLY ACTIVE ALCOHOL
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Disclosed is a method for producing an optically active alcohol including reacting a titanium compound, an aromatic magnesium compound and a carbonyl compound in the presence of an optically active biphenol compound having a predetermined structure and an ether compound having a predetermined structure.
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Page/Page column 19
(2012/02/14)
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- Molecular engineering of coordination pockets in chloro-tris-phenoxo complexes of titanium(IV)
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The chloro-tris-phenoxo complexes [TiCl(OAr)3] (OAr = OC6H4CMe3-4 (1), OC6H3Me2-2,4 (2), OC6H2Me3-2,4,6 (4), OC6H3(CHMe2)2-2,6 (5), OC6H3(CMe3)2-2,4 (6) and OC6H4Ph-2 (8) are prepared by heating 3 equivalents of the phenol and [TiCl4] in toluene. X-ray crystal structure determinations show that 2 is a phenoxy-bridged dimer with the ortho-methyl groups making the beginning of a pocket about the terminal chloro ligand and 6 is a tetrahedral monomer in which the pocket is more well developed by the ortho-tert-butyl groups. Both 2 and 6 react with dmbipy to give [TiCl(OAr)3(dmbipy)] [OAr = OC6H3Me2-2,4 (3) and OC6H3(CMe3)2-2,4 (7)] in which the original pocket is destroyed. Reaction of TiCl4 with 3 equivalents of LiOC6H4Ph-2 in diethyl ether gives [TiCl(OC6H4Ph-2)3(diethyl ether)] (9) for which an X-ray crystal structure determination shows a trigonal bipyramidal coordination geometry with the diethyl ether lying trans to the chloro ligand. The three phenoxide ligands make up the equatorial plane which takes the 2-phenyl substituent on each phenoxo ligand away from the chloro ligand resulting in a partially collapsed cavity. The tied-back analogues of 2 and 6, [TiCl{(OC6H2Me2-2,4-CH2-6) 3N}] (11) and [TiCl({OC6H2(CMe3)2-2,4-CH 2-6}3N)] · diethyl ether (12), are prepared by adding (HOArCH2)3N [Ar = C6H2Me2-2,4 and C6H2(CMe3)2 2,4] to [TiCl(OCHMe2)3] in diethyl ether. An X-ray crystal structure of 12 showed a trigonal bipyramidal structure with a coordination environment about the terminal chloro ligand similar to that found in 6. Complex 12 reacts with pyridine to form the 6-coordinate complex [TiCl({OC6H2(CMe3)2-2,4-CH 2-6}3N)(py)] (13).
- Nielson, Alastair J.,Shen, Chaohong,Waters, Joyce M.
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p. 2039 - 2054
(2008/10/09)
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- Titanium alkoxides as initiators for the controlled polymerization of lactide
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Fourteen titanium alkoxides were synthesized for comparison of their catalytic properties in the bulk and solution polymerization of lactide (LA). In bulk polymerizations, they are effective catalysts in terms of polymer yield and molecular weight. Titanatranes gave polylactides with significantly increased molecular weight over more extended polymerization times, and those with five-membered rings afforded polymers in higher yields and with larger molecular weights than their six-membered ring counterparts. Steric hindrance of the rings was found to significantly affect polymer yields. Increased heterotactic-biased poly(rac-LA) was formed as the number of chlorine atoms increased in TiClx(O-i-Pr)4-x. In solution polymerizations, titanium alkoxides catalyzed controlled polymerizations of LA, and end group analysis demonstrated that an alkoxide substituent on the titanium atom acted as the initiator. That polymerization is controlled under our conditions was shown by the linearity of molecular weight versus conversion. A tendency toward formation of heterotactic-biased poly(rac-LA) was observed in the solution polymerizations. The rate of ring-opening polymerization (ROP) and the molecular weight of the polymers are greatly influenced by the substituents on the catalyst, as well as by factors such as the polymerization temperature, polymerization time, and concentration of monomer and catalyst.
- Kim, Youngjo,Jnaneshwara,Verkade, John G.
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p. 1437 - 1447
(2008/10/08)
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- Method for preparing cyclopropylamines
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PCT No. PCT/EP97/06100 Sec. 371 Date May 6, 1999 Sec. 102(e) Date May 6, 1999 PCT Filed Nov. 5, 1997 PCT Pub. No. WO98/22425 PCT Pub. Date May 28, 1998The present invention relates to a process for preparing cyclopropylamines of the formula wherein R1, R2, R3, R4, and R5 have specified meanings, by reacting (1) a carboxamide of the formula wherein R1, R2, and R3 have specified meanings, with (2) an olefin of the formula wherein R4, R5, and R6 have specified meanings, (3) alkylmagnesium halides or zinc alkyl compounds of the formulaR8-X(VIII),wherein R8 has a specified meaning and X represents MgCl, MgBr, Mgl, ZnCl, ZnBr, Znl, or ZnR8, and (4) orthometallates of the formula (IX) wherein R9 has a specified meaning, Y represents Ti, Zr, or V=O, and Z represents chlorine, bromine, or C1-C4-alkyl, with the provisos that when is Y os Ti or Zr, then is 3 or 4 and r are zero or 1 and the sum q+r=4, and that when Y is V=O, then q represents 3 and r represents zero.
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- On the Chemistry of Acetylenic Titanium Compounds
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Solutions of acetylenic titanium compounds of the type R-CC-Ti(OiPr)3 (5) were prepared in the usual way, and their reactions with various electrophiles were studied.The addition to aldehydes takes place at low temperature; however, for ketones, long reaction times at 0 deg C are necessary.Therefore a complete differentiation between these two functional groups can be achieved.In contrast to alkyl titanium compounds, the alkinyl derivatives are more basic than the corresponding lithium compounds.The use of reagents 5 instead of lithium acetylides does not result in a striking improvement of the diastereoselectivity of addition to chiral aldehydes.The phenyl-substituted reagent (5, R = C6H5) reacts with styrene oxide 25 at the higher substituted carbon atom selectively with 59percent retention.
- Krause, Norbert,Seebach, Dieter
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p. 1845 - 1852
(2007/10/02)
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- Chemoselective Addition of Organotitanium Reagents to Carbonyl Compounds
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The conversion of classical carbanions such as RMgX, RLi, or deprotonated nitriles, sulfones, and carboxylic esters into titanium analogs results in reagents which add chemoselectively to carbonyl compounds in the presence of other functional groups.The standard titanating agent is chlorotriisopropoxytitanium (1).Grignard-type reactions and aldol additions are aldehyde-selective in the presence of ketones.Other functional groups such as alkyl and aryl halides, esters, amides as well as nitro and cyano moieties are tolerated.Discrimination between two aldehydes or two ketones is also possible.Replacing alkoxy ligands by methyl groups at titanium increases reactivity dramatically, relative rates increasing in the series CH3Ti(OCHMe2)3 (CH3)2Ti(OCHMe2)2 (CH3)4Ti.The latter reagent and its zirconium analog methylate sterically hindered and/or enolizable ketones which normally fail to undergo Grignard reactions.The ate complex H2C=CHCH2Ti(OCHMe2)4MgCl (63) is aldehyde-selective, while the amino analog H2C=CHCH2Ti(NMe2)4MgCl (64) adds selectively to ketones in the presence of aldehydes.
- Reetz, Manfred T.,Westermann, Juergen,Steinbach, Rainer,Wenderoth, Bernd,Peter, Roland,et al.
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p. 1421 - 1440
(2007/10/02)
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- Enantioselective Addition of Chiral Organotitanium Derivatives to Aldehydes
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Alkoxy- and aryloxy-organotitanum compounds 2-4 derived from (S)-2-methyl-1-butanol, (R)-2-butanol, (-)-menthol, quinine, cinchonine, and (S)-1,1'-binaphthol are added to aromiatic aldehydes to give optically active alcohols 5-10 in enantioselectivities of up to 88percent e.e., with nucleophilic transfer of methyl, phenyl, and 1-naphthyl groups.The Tables 1-3 list the effects of varying the reagents, the substrates, and the reaction conditions of the new asymmetric synthesis.
- Olivero, Alan G.,Weidmann, Beat,Seebach, Dieter
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p. 2485 - 2488
(2007/10/02)
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