- Disposable cartridge concept for the on-demand synthesis of turbo Grignards, Knochel–Hauser amides, and magnesium alkoxides
-
Magnesium organometallic reagents occupy a central position in organic synthesis. The freshness of these compounds is the key for achieving a high conversion and reproducible results. Common methods for the synthesis of Grignard reagents from metallic magnesium present safety issues and exhibit a batch-to-batch variability. Tubular reactors of solid reagents combined with solution-phase reagents enable the continuous-flow preparation of organomagnesium reagents. The use of stratified packed-bed columns of magnesium metal and lithium chloride for the synthesis of highly concentrated turbo Grignards is reported. A low-cost pod-style synthesizer prototype, which incorporates single-use prepacked perfluorinated cartridges and bags of reagents for the automated on-demand lab-scale synthesis of carbon, nitrogen, and oxygen turbo magnesium bases is presented. This concept will provide access to fresh organomagnesium reagents on a discovery scale and will do so independent from the operator’s experience in flow and/or organometallic chemistry.
- Adamo, Andrea,Berton, Mateo,McQuade, D. Tyler,Sheehan, Kevin
-
supporting information
p. 1343 - 1356
(2020/07/10)
-
- PROCESS FOR PRODUCING PHOSPHONIUM BORATE COMPOUND, NOVEL PHOSPHONIUM BORATE COMPOUND, AND METHOD OF USING THE SAME
-
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.
- -
-
Page/Page column 68-69
(2008/06/13)
-
- Production processes for triorganomonoalkoxysilanes and triorganomonochlorosilanes
-
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.
- -
-
Page/Page column 21; 22; 23-24; 26; 28; 29
(2008/06/13)
-
- Active Magnesium from Catalytically Prepared Magnesium Hydride or from Magnesium Anthracene and its Uses in the Synthesis
-
Highly reactive, pyrophoric forms of magnesium with specific surface areas of 20-109 m2/g (Mg*) can be generated by the dehydrogenation of catalytically prepared magnesium hydride (MgH2*) or by decomposition of magnesium anthracene * 3 THF (4).The decomposition of 4, with recovery of anthracene and THF, may be accomplished both thermally and by ultrasound in an organic solvent (toluene, n-heptane) or thermally in the solid state in vacuo.Mg* obtained by the latter method exhibits only weak reflections in the X-ray powder diagram and has, in comparison to other mentioned Mg* species, the highest reactivity toward hydrogen.Diverse Grignard compounds can be prepared under mild conditions (* from MgH2* or 4.The cleavage of THF with formation of 1-oxa-2-magnesiacyclohexane (2) is possible by employing Mg* from NgH2* or 4.
- Bartmann, Ekkehard,Bogdanovic, Borislav,Janke, Nikolaus,Liao, Shijan,Schlichte, Klaus,et al.
-
p. 1517 - 1528
(2007/10/02)
-
- Use of Magnesium Anthracene * 3 THF in Synthesis: Generation of Grignard Compounds and Other Reactions with Organic Halides
-
The course (a), (b), (c) (Scheme 1) of the reaction of magnesium anthracene * 3 THF (1) with organic halides (RX) is dependent on the nature of RX.With alkyl halides in THF 1 reacts as a nucleophile, whereby primary as well as secondary alkyl halides produce dialkyldihydroanthracenes (4-4'') and tertiary alkyl halides yield primarily monoalkyl-substituted dihydroanthracenes (2, 2').With bromo- and iodobenzene in THF 1 reacts predominantly as a radical with H atom abstraction from the solvent affording benzene and 9.The formation of Grignard compounds (5) and anthracene (6), originating from primary and secondary alkyl and aryl halides and 1 in toluene or ether at elevated temperatures, is not caused by the reaction of 1 but by the "active magnesium" (Mg*) formed by decomposition of 1 in these solvents.In contrast, allyl, propargyl, and benzyl halides react with 1 independently of the solvent under mild conditions to produce 5 and 6.Allyl- and the difficultly accessible allenylmagnesium chloride can be prepared in THF at -78 and 0 deg C, respectively, from the corresponding halides and ordinary Mg powder via catalytic amounts of 1.
- Bogdanovic, Borislav,Janke, Nikolaus,Kinzelmann, Hans-Georg
-
p. 1507 - 1515
(2007/10/02)
-
