53723-94-7

Upstream product

• 3282-30-2 pivaloyl chloride 
• 14630-40-1 Bis(trimethylsilyl)ethyne 
• 54655-07-1 lithium trimethylsilylacetylenide 
• 64214-60-4 N-methoxy-N-methylpivalamide 
• 1066-54-2 trimethylsilylacetylene 
• 71321-14-7 4,4-dimethyl-1-(trimethylsilyl)pent-1-yn-3-ol 

Downstream Products

• 5891-25-8 4,4-dimethyl-1-pentyn-3-one 
• 82202-02-6 5-trimethylsilyl-2,2-dimethyl-4-(1-phenylthiobutyl)hex-4-en-3-one 
• 1018459-26-1 1-[3-(4-methoxyphenyl)-5-(trimethylsilyl)isoxazol-4-yl]-2,2-dimethylpropan-1-one 
• 1151509-45-3 C₁₇H₃₀OSi 

Relevant academic research and scientific papers

Steric/π-Electronic Insulation of the carbo-Benzene Ring: Dramatic Effects of tert-Butyl versus Phenyl Crowns on Geometric, Chromophoric, Redox, and Magnetic Properties

Hexa-tert-butyl-carbo-benzene (C18tBu6) and three phenylated counterparts (C18tBumPh6?m; m=4, 2) have been synthesized. The peralkylated version (m=6) provides experimental access to intrinsic features of the insulated C18 core independently from the influence of π-conjugated substituent. Over the series, structural, spectroscopic, and electrochemical properties are compared with those of the hexaphenylated reference (m=0). Anchoring tBu substituents at the C18 macrocycle is shown to enhance stability and solubility, and to dramatically modify UV/Vis absorption and redox properties. Whereas all carbo-benzenes reported previously were obtained as dark-reddish/greenish solids, crystals and solutions of C18tBu6 happen to be yellow (λmax=379 vs. 472 nm for C18Ph6). In comparison to C18Ph6, the reduction of C18tBu6 remains reversible, but occurs at twice as high an absolute potential (E1/2=?1.36 vs. ?0.72 V). Systematic XRD analyses and DFT calculations show that the C18 ring symmetry is the nearest to D6h for m=6, which indicates a maximum geometric aromaticity. According to calculated nucleus-independent chemical shifts (NICS), the macrocyclic magnetic aromaticity is also maximum for C18tBu6: NICS(0)=?17.2 ppm versus (?18.0±0.1) ppm for the theoretical references C18H6 and C18F6, and ?13.5 ppm for C18Ph6. Accurate correlations of NICS(0) with experimentally recorded or calculated maximum UV/Vis absorption wavelengths, λmax, and chemical hardness, η=ELUMO?EHOMO, are evidenced.

Mild and expedient asymmetric reductions of α,β-unsaturated alkenyl and alkynyl ketones by TarB-NO2 and mechanistic investigations of ketone reduction

A facile and mild reduction procedure is reported for the preparation of chiral allylic and propargyl alcohols in high enantiomeric purity. Under optimized conditions, alkynyl and alkenyl ketones were reduced by TarB-NO 2 and NaBH4 at 25 °C in 1 h to produce chiral propargyl and allylic alcohols with enantiomeric excesses and yields up to 99%. In the case of α,β-unsaturated alkenyl ketones, α-substituted cycloalkenones were reduced with up to 99% ee, while more substituted and acyclic derivatives exhibited lower induction. For α,β-ynones, it was found that highly branched aliphatic ynones were reduced with optimal induction up to 90% ee, while reduction of aromatic and linear aliphatic derivatives resulted in more modest enantioselectivity. Using the (l)-TarB-NO2 reagent derived from (l)-tartaric acid, we routinely obtained highly enantioenriched chiral allylic and propargyl alcohols with (R) configuration. Since previous models and a reduction of a saturated analogue predicted propargyl products of (S) configuration, a series of new mechanistic studies were conducted to determine the likely orientation of aromatic, alkenyl, and alkynyl ketones in the transition state.

The Ever-Elusive Tetra-ferf-butylethene (TTBE, 3,4-Di-ferf-butyl- 2,2,5,5-tetramethylhex-3-ene): Further insight on its preparation

Diketone 4 was prepared by hydrolysis of hexendiyne 5,the latter being available through McMurry coupling of acetyl- enic ketone 26. Upon treatment with dimethyltitanium dichlo- ride, 4 cyclizes into fully alkylated furan derivative 30;the still unknown t

Novel microwave-assisted one-pot synthesis of isoxazoles by a three-component coupling-cycloaddition sequence

The consecutive Sonogashira coupling of acid chlorides with terminal alkynes, followed by 1,3-dipolar cycloaddition under dielectric heating of in situ generated nitrile oxides from hydroximinoyl chlorides furnishes isoxazoles in moderate to good yields i

Asymmetric reduction of ethynyl ketones and ethynylketoesters by secondary alcohol dehydrogenase from Thermoanaerobacter ethanolicus

Secondary alcohol dehydrogenase (SADH) from Thermoanaerobacter ethanolicus, an NADP-dependent, thermostable oxidoreductase, reduces ethynyl ketones and ethynylketoesters enantioselectively to the corresponding propargyl (propargyl = prop-2-ynyl) alcohols. Ethynyl ketones, in general, are reduced with moderate enantioselectivity (with the exception of 4-methylpent-l-yn-3-one, which gives the (S)-alcohol with >98% ee). Although ethynyl ketones bearing a small (up to n-propyl) alkyl substituent are reduced to (S)-alcohols, larger ethynyl ketones give (R)-alcohols. In contrast, ethynylketoesters are converted to (R)-ethynylhydroxyesters of excellent optical purity. Unexpectedly, isopropyl ethynylketoesters give higher chemical yields and higher enantioselectivities of ethynylhydroxyesters than methyl or ethyl ethynylketoesters. The optically pure ethynylhydroxyesters may serve as useful chiral building blocks for asymmetric synthesis.

A convenient synthesis of masked β-ketoaldehydes by the controlled addition of nucleophiles to (trimethylsilyl)ethynyl ketones

The controlled addition of nucleophiles to (trimethylsilyl)ethynyl ketones provides a facile route to β-ketoacetals, β-alkoxy-α,β-unsaturated ketones or vinylogous amides depending on the choice of reaction conditions.