“…We suppose that the attack of the fluoride-ion at silicon leads to the activation of the Si-C sp bond and further nucleophilic attack of the trimethylsilylethynyl group to the carbonyl group of published in the previous paper [10]. and 16a agree with the data PhCHO conversion was 40%.…”
Section: Resultssupporting
confidence: 85%
“…Among these reactions the synthesis of 1-trimethylsiloxy-3-aryl-2-propynes realised by the addition of 1-phenyl-2-(trimethylsilyl)acetylene or other terminal silylacetylenes to carbonyl compounds in the Bu 4 NF/THF [3,4], KF/18-crown-6/CH 2 CI 2 or THF [5], KF/DMF [6], Ph 4 P + HF 2 /DMF [7], Bu 4 N + HF 2~ [8] systems was described. Recently we have reported CsF/18-crown-6 mediated reactions of trimethylsilylacetylene with carbonyl compounds and/or terminal aryl and hetaryl acetylenes [10], To investigate the influence on their reactivity of the 14 group element present in the disubstituted acetylenes Me 3 SiC^CMMe 3 (M = C, Si, Ge, Sn) the cesium fluoride mediated reactions with aryl aldehydes ArCHO and ketones ArC(0)Me (Ar = phenyl, 2-pyridyl, 2-furyl, 2thienyl, 2-methyl-5-thienyl, 2,5-dimethyl-3-thienyl) have been carried out. Recently we have reported CsF/18-crown-6 mediated reactions of trimethylsilylacetylene with carbonyl compounds and/or terminal aryl and hetaryl acetylenes [10], To investigate the influence on their reactivity of the 14 group element present in the disubstituted acetylenes Me 3 SiC^CMMe 3 (M = C, Si, Ge, Sn) the cesium fluoride mediated reactions with aryl aldehydes ArCHO and ketones ArC(0)Me (Ar = phenyl, 2-pyridyl, 2-furyl, 2thienyl, 2-methyl-5-thienyl, 2,5-dimethyl-3-thienyl) have been carried out.…”
The CsF / 18-crown-6 mediated reactions of disubstituted acetylenes Me 3 SiC^CMMe 3 (M = C, Si, Ge, Sn) with carbonyl compounds in benzene were studied. In all cases the interaction proceeds with cleavage of the Si-C sp bond and can be considered as the addition of ethynylsilane to the carbonyl C=0 bond. The formation of bissiloxy derivatives was detected for acetylenes with M=Si and Sn. The cleavage of the Ge-C sp does not occur under the conditions used. Transmetallation of 1-trimethylsilyl-2-trimethylstannylacetylene was observed to give a mixture of symmetrical bissilyl-and bisstannylacetylenes with the following bis(trimethylsilyl)acetylene addition to the carbonyl compound, the bisstannyl analogue being inactive in CsF / 18-crown-6 mediated conditions. These processes open a simple way for the synthesis of new ethynylsubstituted derivatives of germanium and tin. 1 H NMR spectra were recorded on a Varian 200 Mercury spectrometer (200 MHz) using CDCI 3 as a solvent. Mass spectra were registered on a GC-MS HP 6890 (70 eV) apparatus. GC analysis was performed on a Chrom-5 instrument equipped with a flame-ionization detector using a glass column packed with 5% OV-101/Chromosorb W-HP (80-100 mesh, 1.2 m χ 3 mm). Carbonyl compounds 1-12 were purified by distillation in vacuo prior the use. Bis(trimethylsilyl)acetylene (Aldrich) was used without purification. 1-Trimethylsilyl-2trimethylgermylacetylene [11], 1-trimethylsilyl-2-trimethylstannylacetylene [11] and 1-tert-butyl-2trimethylsilylacetylene [12] were prepared according to the procedures described in [13,14]. CsF was calcinated at ca 200°C during 1 h. Benzene was distilled over CaH 2 and kept over molecular sieves 4A.General procedure for the synthesis of 13 -42. Freshly calcinated CsF (0.03 g, 0.2 mmol) was to a mixture of 1 -12 (1mmol) and 18-crown-6 (0.026 g, 0.1 mmol) in 1.5 ml of dry benzene under argon atmosphere added. After 5-minute stirring the corresponding acetylene (1 mmol) 243 Brought to you by | Purdue University Libraries
“…We suppose that the attack of the fluoride-ion at silicon leads to the activation of the Si-C sp bond and further nucleophilic attack of the trimethylsilylethynyl group to the carbonyl group of published in the previous paper [10]. and 16a agree with the data PhCHO conversion was 40%.…”
Section: Resultssupporting
confidence: 85%
“…Among these reactions the synthesis of 1-trimethylsiloxy-3-aryl-2-propynes realised by the addition of 1-phenyl-2-(trimethylsilyl)acetylene or other terminal silylacetylenes to carbonyl compounds in the Bu 4 NF/THF [3,4], KF/18-crown-6/CH 2 CI 2 or THF [5], KF/DMF [6], Ph 4 P + HF 2 /DMF [7], Bu 4 N + HF 2~ [8] systems was described. Recently we have reported CsF/18-crown-6 mediated reactions of trimethylsilylacetylene with carbonyl compounds and/or terminal aryl and hetaryl acetylenes [10], To investigate the influence on their reactivity of the 14 group element present in the disubstituted acetylenes Me 3 SiC^CMMe 3 (M = C, Si, Ge, Sn) the cesium fluoride mediated reactions with aryl aldehydes ArCHO and ketones ArC(0)Me (Ar = phenyl, 2-pyridyl, 2-furyl, 2thienyl, 2-methyl-5-thienyl, 2,5-dimethyl-3-thienyl) have been carried out. Recently we have reported CsF/18-crown-6 mediated reactions of trimethylsilylacetylene with carbonyl compounds and/or terminal aryl and hetaryl acetylenes [10], To investigate the influence on their reactivity of the 14 group element present in the disubstituted acetylenes Me 3 SiC^CMMe 3 (M = C, Si, Ge, Sn) the cesium fluoride mediated reactions with aryl aldehydes ArCHO and ketones ArC(0)Me (Ar = phenyl, 2-pyridyl, 2-furyl, 2thienyl, 2-methyl-5-thienyl, 2,5-dimethyl-3-thienyl) have been carried out.…”
The CsF / 18-crown-6 mediated reactions of disubstituted acetylenes Me 3 SiC^CMMe 3 (M = C, Si, Ge, Sn) with carbonyl compounds in benzene were studied. In all cases the interaction proceeds with cleavage of the Si-C sp bond and can be considered as the addition of ethynylsilane to the carbonyl C=0 bond. The formation of bissiloxy derivatives was detected for acetylenes with M=Si and Sn. The cleavage of the Ge-C sp does not occur under the conditions used. Transmetallation of 1-trimethylsilyl-2-trimethylstannylacetylene was observed to give a mixture of symmetrical bissilyl-and bisstannylacetylenes with the following bis(trimethylsilyl)acetylene addition to the carbonyl compound, the bisstannyl analogue being inactive in CsF / 18-crown-6 mediated conditions. These processes open a simple way for the synthesis of new ethynylsubstituted derivatives of germanium and tin. 1 H NMR spectra were recorded on a Varian 200 Mercury spectrometer (200 MHz) using CDCI 3 as a solvent. Mass spectra were registered on a GC-MS HP 6890 (70 eV) apparatus. GC analysis was performed on a Chrom-5 instrument equipped with a flame-ionization detector using a glass column packed with 5% OV-101/Chromosorb W-HP (80-100 mesh, 1.2 m χ 3 mm). Carbonyl compounds 1-12 were purified by distillation in vacuo prior the use. Bis(trimethylsilyl)acetylene (Aldrich) was used without purification. 1-Trimethylsilyl-2trimethylgermylacetylene [11], 1-trimethylsilyl-2-trimethylstannylacetylene [11] and 1-tert-butyl-2trimethylsilylacetylene [12] were prepared according to the procedures described in [13,14]. CsF was calcinated at ca 200°C during 1 h. Benzene was distilled over CaH 2 and kept over molecular sieves 4A.General procedure for the synthesis of 13 -42. Freshly calcinated CsF (0.03 g, 0.2 mmol) was to a mixture of 1 -12 (1mmol) and 18-crown-6 (0.026 g, 0.1 mmol) in 1.5 ml of dry benzene under argon atmosphere added. After 5-minute stirring the corresponding acetylene (1 mmol) 243 Brought to you by | Purdue University Libraries
“…In a similar manner as trimethyl(aryl)silanes, trimethyl(alkynyl)silanes, Me 3 SiC⋮CR, can be used as transfer reagents in fluoride substitutions . Reactions of trimethyl(alkynyl)silanes under fluoride ion initiation in organic synthesis were reported by Abele et al , The reactions of several trimethyl(alkynyl)silanes with xenon difluoride and tetramethylammonium fluoride in dichloromethane or a dichloromethane/propionitrile mixture were investigated at temperatures between −78 and −30 °C by multinuclear NMR spectroscopy (Scheme ). 1 …”
Alkynylxenon(II) fluorides, RCC(triple bond)XeF, have been prepared from the reactions of the corresponding trimethyl(alkynyl)silanes, Me3(-)SiC(triple bond)CR, and XeF2 in the presence of [NMe4F in common organic solvents at low temperature. The existence of the linear unit C(triple bond)C-Xe-F was proved for PhC(triple bond)CXeF by the 19F-13C NMR correlation method using the HMBC pulse sequence.
“…The silylated adducts 75 and 76 were formed as by-products in the reaction of 74 with trimethylsilylacetylene or with trimethylsilylacetylene and carbonyl compound, respectively (Scheme 28)[42], The trimethylsilylacetylene adducts74 onto the C=0 double bond were prepared as main products (15 -66 % yield) in all reactions.…”
mentioning
confidence: 99%
“…The experiments showed that 20 mol.% of CsF to substrates 69 were optimal amount of catalyst (Scheme 30)[42], Silylated acetylenes can be successfully hydroxymethylated with parafomaldehyde in the presence of fluoride. The experiments showed that 20 mol.% of CsF to substrates 69 were optimal amount of catalyst (Scheme 30)[42], Silylated acetylenes can be successfully hydroxymethylated with parafomaldehyde in the presence of fluoride.…”
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