- Homologation of halostannanes with carbenoids: a convenient and straightforward one-step access to α-functionalized organotin reagents
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A direct, single synthetic homologative transformation of halostannanes into mono- or di-substituted methyl analogues is documented. Critical for the success of the operation is the excellent nucleophilicity of carbenoid-like methyllithium reagents (LiCHXY, X, Y = halogen, OR, and CN): by simply individuating the reagents' substitution pattern, the desired functionalized fragment is delivered to the electrophile. The wide scope of the protocol is evidenced also in the case of analogous halogermanium compounds. The tandem homologation-quenching with nucleophiles and the use of α-chloroallyllithium is also discussed.
- Touqeer, Saad,Castoldi, Laura,Langer, Thierry,Holzer, Wolfgang,Pace, Vittorio
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supporting information
p. 10112 - 10115
(2018/09/13)
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- One-pot synthesis three iodine methyl butyl tin
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The invention discloses a synthesis method of a medical intermediate iodomethyl tributyltin. The synthesis method specifically comprises the following steps: dropwise adding n-butyllithium to the raw materials including diiodomethane and tributyltin chloride at minus 78 DEG C to carry out in-situ reaction to generate the target product iodomethyl tributyltin. The method has the obvious advantages that the reaction raw materials are easy to obtain; the reaction operation is simple; large-scale production is easy to achieve; the yield is high; the purity is good; the production cost is low.
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Paragraph 0028; 0029; 0031; 0033; 0035
(2018/05/24)
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- SnAP reagents for the synthesis of piperazines and morpholines
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Substituted piperazines and morpholines are valuable structural motifs in biologically active compounds, but are not easily prepared by contemporary cross-coupling approaches. In this report, we introduce SnAP reagents for the transformation of aldehydes into N-unprotected piperazines and morpholines. This approach offers simple, mild conditions compatible with aromatic, heteroaromatic, aliphatic, and glyoxylic aldehydes and provides mono- and disubstituted N-heterocycles in a single step.
- Luescher, Michael U.,Vo, Cam-Van T.,Bode, Jeffrey W.
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supporting information
p. 1236 - 1239
(2014/03/21)
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- On the configurational stability of chiral, nonracemic fluoro- and iodo-[D1]methyllithiums
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Enantiomerically pure fluoro-[D1]methyllithium and iodo-[D 1]methyllithiums of up to 92% ee were generated by transmetalation of the corresponding stannanes with MeLi in THF at various temperatures. The intermediate halo-[D1]methyllithiums were trapped with benzaldehyde or acetophenone already present in excess in the reaction mixture to either give halohydrins or to disintegrate to carbene. The fluoro-[D1] methyllithiums were found to be microscopically configurationally stable within the tested range of -95 to 0°C, but chemically only stable at temperatures below -95°C due to a rapidly increasing portion disintegrating to carbene. The iodo-[D1]methyllithiums were configurationally labile relative to the rate of addition to PhCHO at all temperatures tested (-95 to -30°C). Disintegration to carbene interfered as well. The microscopic configurational stability of enantiomerically pure fluoro-[D1]methyllithiums prepared by tin-lithium exchange in the presence of excess benzaldehyde or acetophenone has been investigated. Depending on the reaction temperature, a portion of the generated fluoro-[D1]methyllithiums was added to the electrophiles to give fluorohydrins; the remaining portions disintegrated to carbene and LiF (see scheme).
- Kail, Dagmar C.,Malova Krizkova, Petra,Wieczorek, Anna,Hammerschmidt, Friedrich
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p. 4086 - 4091
(2014/04/17)
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- SnAP reagents for the transformation of aldehydes into substituted thiomorpholines - An alternative to cross-coupling with saturated heterocycles
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It's a SnAP! The transformation of aldehydes into N-unsubstituted 3-thiomorpholines provides a convenient alternative to metal-catalyzed cross-coupling reactions, which are generally unsuited to the functionalization of saturated N-heterocycles. A copper-mediated radical cyclization is the key to the mild conditions, high functional group tolerance, and broad substrate scope offered by these reagents. Copyright
- Vo, Cam-Van T.,Mikutis, Gediminas,Bode, Jeffrey W.
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p. 1705 - 1708
(2013/04/10)
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- COMPOUNDS
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The present invention features compounds of formula (I): and salts thereof, pharmaceutical compositions comprising said compounds, and uses of such compounds in treating or preventing viral infections, such as HCV infections, and diseases associated with such infections.
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Page/Page column 60
(2012/06/01)
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- HYDROXYMETHYLBORON COMPOUNDS
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The present invention provides compounds which are useful as safe substitutes for the organotin reagent used in coupling reaction for the oxymethylation of aromatic rings, such as alkoxymethylation or hydroxymethylation, with a palladium catalyst and which can dispense with chromatographic purification with silica gel in the production and are suitable for mass production; and compounds applicable even to the oxymethylation of aromatic ring substrates which do not permit coupling reaction by conventional technique or have low reactivity.
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Page/Page column 23
(2010/11/29)
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- Efficient synthesis of bromo- and iodomethyltributyltin
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An efficient two-step procedure for the preparation of bromo- and iodotributyltin starting from tributyltin hydride is described.
- Ahman,Somfai
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p. 1117 - 1120
(2007/10/02)
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- The influence of the 5-methyl group in bacteriorhodopsin
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All-E-5-bromo-5-demethylretinal was prepared in 6percent yield starting from 4,4-dimethyl-2-cyclohexenone via 2-bromo-6,6-dimethyl-1-cyclohexenecarboxaldehyde.The crucial step in the preparation of the intermediate is a 2,3 Wittig rearrangement. 5-Bromo-5
- Groesbeeck, M.,Vries, E. F. J. de,Berden, J. A.,Lugtenburg, J.
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p. 303 - 308
(2007/10/02)
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