3-Trimethylsilyl-propynal

Dithians such as (261) are synthesized from 3-(trimethylsilyl)propynal and propylene-1,3-dithiol, and are versatile intermediates. ... 

Bis(trimethylsilyl)propyne, 141 Bis(trimethylsilyl)terminai alkynols, 97 Borane-dimethyl sulphide. 84 Bromination-dcsilicobromination, 17-18... 

Similar metalation studies were carried out on l,3-bis(trimethylsilyl)propyne. The IR bands observed in the 2200-1600 cm region of acetylenes, allenes and aU the Uthiated derivatives are summarized in Table 8. 

M. Langsam, M. Anand and E.J. Karwacki, Substituted Propyne Polymers I. Chemical Surface Modification of Poly [ 1 -(trimethylsilyl)propyne] for Gas Separation Membranes, Gas Sep. Purif. 2, 162 (1988). 

The diffusion of gases through a polymer matrix is determined by the mobility of gas molecules through the matrix. The diffusion coefficient is therefore, at least partially determined by the free volume size of the polymer. It has been shown, for example, that there is a correlation between the free volume measured by PAL and the diffusivity of carbon dioxide in a seriers of polycarbonates [58], In a study of poly (trimethylsilyl propyne) (PTMSP), which has an extremely high gas permeability and diffusion coefficients, it was found that the lifetime data could be resolved into four components [59]. The longest lifetime component (T4) had a lifetime of... 

Pinnau I, Casillas CG, Morisato A, and Freeman BD. Long-term permeation properties of poly(l-trimethylsilyl-propyne) membranes in hydrocarbon-vaport environment. J. Polym. Sci. PartB Polym. Phys. 1997 35 1483-1490. 

Propynyl bromide gives both the trimethylsilyl propyne and allene derivatives (3 1) in a 71% yield on reaction with TMSCI [128], and l,4-bis(trimethylsilyl)but-2-ene results from the TMSCI reaction with l,4-dibromobut-2-ene [129]. 

The reaction has been extended to a-silyl lactones and lactams. Other stabilizing groups have been demonstrated to be effective. For example, the Peterson reagent formed from bis(trimethylsilyl)propyne (357) and that formed from a-silyl acetonitrile derivatives (358) both give the (Z)-alkene as the predominant product (equation 84). ... 

Anneiated benzenes.1 Vollhardt s cocyclization of bis(trimethylsilyl)ethyne with a.tu-diynes has been extended to several new partners. Thus a,trimethylsilyl)propyne and trimethylsilylalkynes. Examples are shown in equations (I) and (II). 

Bis(trimethylsilyl)propyne, 126 Bis(trimethylsilyl) sulfate, 44,196 Bis(triphenylphospliine)copper(I) tetra-... 

The reaction of trichlorocyclopropenylium ion 5 with acetylenic compounds such as 1,2-bis(trimethylsilyl)acetylene and l-(trimethylsilyl)propyne gave the methylenecyclopropene 6 and cyclopropenone 7 containing ethynyl groups by substitution, whereas the reaction with phenylacetylene or l-phenyl-2-(trimethylsilyl)acetylene afforded the ring-opened products 8 via addition reactions. 

A suspension of 1,2,3-trichlorocyclopropenylium tetrachloroaluminate in CH2CI2 (20 mL) was prepared from AICI3 (1.33 g, 10 mmol) and tetrachlorocyclopropene (1.96 g, 11 mmol). After 15 min, CH2CI2 (80 mL) was added, and the suspension was cooled to — 42 "C. To the strirred suspension was added dropwise over 30 min l-(trimethylsilyl)propyne (2.27 g, 20 mmol). The solution was stirred for 1 h at — 42°C and allowed to reach 20 C over 1 h. It was then poured into ice-water, and the organic layer was further washed with H2O and dried. After evaporation of the solvent, the remaining brown oil was purified by flash chromatography (hexane/EtOAc 95 5 to 8 2). Recrystallization (EtjO) gave moisture-sensitive, colorless crystals yield 0.647 g (50%) mp 109 110 C. 

This organocopper reagent is prepared by addition of lithio-l-trimethylsilyl-propyne (2, 239-241) to an ether slurry of cuprous iodide (1.1 eq.) at -78° (N2) gradual warming to -20 to -10° produces a dark brown heterogeneous solution of(l). 

Silylated enynes. Condensation of 3,3-bis(trimethylsilyl)propyne with aldehydes provides predominantly ( )-l-trimethylsilylalk-3-en-l-ynes (8 examples, 48-60%). 

Attempted coupling with lithio-l-trimethylsilyl propyne to give the enediyne... 

Lithiation of commercially available bromoarenes (281) followed by treatment with zirconocene (methyl) chloride affords zirconocene complexes of substituted benzynes (283), which react with symmetric alkynes and l-(trimethylsilyl)propyne to give single regioisomeric zirconacycles, (284) and (285), respectively (Scheme 66). Both (284) and (285) react with disulfur dichloride to produce benzothiophenes (286) and (287), respectively, in 60-80% isolated yields in a one-pot procedure <89JOC2793>. Protodesilylation of (287) can be accomplished in >90% yield to give the corresponding 2-unsubstituted benzothiophenes by treatment with tetrabutylammonium fluoride in tetrahydrofuran. Application of the procedure to the preparation of 2,3-dihydrobenzo[6]thiophenes was also reported <9iOM537>. 

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