Propyne 1,3-diphenyl

After the initial claim of the synthesis of an oxirene (by the oxidation of propyne Section 5.05.6.3.1) this system reappeared with the claim 31LA(490)20l) that 2-chloro-l,2-diphenyl-ethanone (110) reacted with sodium methoxide to give diphenyloxirene (111), but it was later shown (52JA2082) that the product was the prosaic methoxy ketone (112 Scheme 97) (the formation of 111 from 110 would be an a-elimination carbene-type reaction). Even with strong, nonnucleophilic bases, (110) failed to provide evidence of diphenyloxirene formation (64JA4866). 

Whereas the Rh2(OAc)4-catalyzed addition of diazoalkanes to propargyl alcohols readily gives the insertion of the carbene into the 0-H bond, with only a small amoimt of cyclopropenation of the resulting propargylic ether [54] the 2-diazopropane 59 reacts at 0 °C with l,l-diphenyl-2-propyn-l-ol 62a in dichloromethane and exclusively gives, after 10 h of reaction, only the adduct 63a isolated in 75% yield and corresponding to the regioselective 1,3-dipolar cycloaddition of the 2-diazopropane to the alkyne C - C bond (Scheme 15). 

The regiochemistry of Al-H addition to unsymmetrically substituted alkynes can be significantly altered by the presence of a catalyst. This was first shown by Eisch and Foxton in the nickel-catalyzed hydroalumination of several disubstituted acetylenes [26, 32]. For example, the product of the uncatalyzed reaction of 1-phenyl-propyne (75) with BujAlH was exclusively ds-[3-methylstyrene (76). Quenching the intermediate organoaluminum compounds with DjO revealed a regioselectivity of 82 18. In the nickel-catalyzed reaction, cis-P-methylstyrene was also the major product (66%), but it was accompanied by 22% of n-propylbenzene (78) and 6% of (E,E)-2,3-dimethyl-l,4-diphenyl-l,3-butadiene (77). The selectivity of Al-H addition was again studied by deuterolytic workup a ratio of 76a 76b = 56 44 was found in this case. Hydroalumination of other unsymmetrical alkynes also showed a decrease in the regioselectivity in the presence of a nickel catalyst (Scheme 2-22). 

Scheme 1 Synthesis of the allenylidene complex 1 from l,l-diphenyl-2-propyn-l-ol...

Other synthetic methodologies have been used to prepare the unusual octahedral osmium(II) allenylidenes [OsH(=C=C=CPh2)(NCMe)2(PiPr3)2][BF4] and [Os k (C,0)-C(C02Me)=CH2 (=C=C=CPh2)C0)(PiPr3)2][BF4] from l,l-diphenyl-2-propyn-l-ol [22]. 

To a flask containing 12.4 gm (0.037 mole) of l-(a-naphthyl)-l,3-diphenyl-2-propyn-l-ol in 50 ml of dry ether is added 2.0 gm (0.015 mole) of phosphorus trichloride in 10 ml of ether. The solution is stirred at room temperature for 2 hr, filtered, the solid washed with dry ether, and dried to afford 6.5 gm (50 %),... 

A series of cationic, strapped, r)6 ri1 ri1-arene complexes of ruthenium(II) (82) containing both carbon and phosphorus as the auxiliary atoms has been obtained by a coupling reaction of the iminophosphorane complexes 83 with an excess of 1, l-diphenyl-2-propyn-l-ol, the p-cymene in 83 being displaced by one of the phenyl... 

Di(3-phenyl-2-propyn-l-yl)ether (394) yielded 4,6-diphenyl-l,3-dihydrothieno[3,4-c]furan (395) in the presence of equimolar amounts of RhCl3 3H20 and aliquat-336 <93PS(79)87>. 

To a 500-ml reaction flask were added, l,l-diphenyl-2-propyn-l-ol (0.1 mol, 20.8 g, Farchan Laboratories), 2-naphthol (0.11 mol, 15 g) and 200 ml of toluene. The mixture was warmed to 55°C with stirring while dodecylbenzenesulfonic acid was added dropwise until a permanent dark red-black color was obtained. The temperature was maintained at 55°C until thin-layer chromatography (TLC) indicated the reaction was complete (approximately 1 h). Then the mixture was poured into an equal volume of 10% aqueous sodium hydroxide, shaken, and the organic fraction separated. The toluene solution was washed with water, phase separated, and the solvent removed on a rotary evaporator. The resulting light tan crystals were slurried with hexane, suction filtered, and dried to yield 18.4 g of product with a melting point range of 156-158°C. 

SYNS l,l-DIPHENYL-2-PROPYN-I-OL CYCLOHEXANECARBAMATE l,l-DIPHENYL-2-PROPYNYL ESTER CYCLOHEXANECARBAMIC ACID ENPROMATE... 

Thiabenzene I-oxide. The reaction of 1,3-disubstituted 2-propynones such as l,3-diphenyl-2-propyn-I-onc (1) with dimethyloxosulfonium methylide in DMSO at 16.5° gives l-mcthyl-3,5-disubstituted thiabenzene I-oxides in the case of (I) the product is l-methyl-3,5-diphenylthiabenzene l-oxide (3), obtained in 76% yield. If the reaction is carried out in THF-DMSO at - 8°, the intermediate (2) can be isolilted it probably arises by Michael addition of the reagent to (I). 

Transmetalations of allenylstannanes represent an important conceptual development, which substantially increases the potential utility of these reagents. i 4 Corey established an early example via the transmetalation of 3-triphenylstannyl-l-propyne with (/ ,f )-B-bromo-4,5-diphenyl-l,3-diaza-2-borolidine (R,R-22S) yielding the intermediate formation of allenylborane 334. Low temperature condensations of 334 with aldehydes occurred via closed transition states in which the chirality of the Stein auxiliary determined the stereogenicity of the enantioenriched -alcohol 335 (Scheme 5.2.70). ... 

The lower reactivity of iridium complexes requires the use of more activated precursors. Thus, the neutral square-planar derivatives Zra .v- IrCI =C=C=C(R)Ph (Pz -Prs)2] (R = Ph, f-Bu) have been prepared from [IrH2Cl(Pz-Pr3)2] and the appropriate alkynol, via UV-promoted or CF3CO2H-catalyzed dehydration of the initially formed hydride-alkynyl intermediates [IrHCl C=CC(R)Ph(OH) (Pz-Pr3)2] [78, 81]. The cationic species [Ir(=C=C=CPh2)(/ -diene)( PR3) [BF4] (diene = COD, PR3 = PCys diene - TFB, PR3 - PCys, P/-Prs) are also known [211], They were synthesized by reacting the methoxo compounds [Ir(OMe)(z/ -diene)(PRs) with l,l-diphenyl-2-propyn-l-ol, followed by dehydration of the resulting alkynyl derivatives [Ir C=CCPh2(OH) (77 -diene)(PRs)] with stoichiometric amounts of HBF4. 

Benzoylphenylacetylene (l,3-diphenyl-2-propyn-l-one) 490 Phenylacetylene is dissolved in the five- to ten-fold amount of anhydrous ether and brought into contact with the calculated amount of sodium wire under ether. Hydrogen is at once evolved and a granular coating of sodium phenylacetylide is formed on the surface of the metal. The reaction is allowed to proceed with occasional shaking. The ether may then be cautiously distilled off, with exclusion of moisture, but that is unnecessary for synthesis of most acetylenic ketones. 

The ri2-H2 or f/2-Si-H complexes could be relevant in Eq. (9.60), although the isolable complex Os(SiEt3)Cl(H2XCOXP,Pr3)2 proposed as an intermediate contains f/2-H2, which is favored over the OsH(if2-HSiEt3) structure in theoretical studies also (see Chapter 4). A related cationic complex [OsH(H2XCOXP Pr 3)2]+ acts as a template for a noncatalytic C-C coupling reaction between methyl pro-piolate and l,l-diphenyl-2-propyn-l-ol.116... 

Figure 10 Alkyne cobalt carbonyl complexes of the steroid RU 486 16, zearalenone 17, methotrexate 18, 17a-propynyl ethynylestradlol 19, 11/3-ethynylestradlol 20, aspirin 21, diphenyl aoetylene 22, and 2-propyn-1-ol 23.

The anti-proliferative effects of some dicobalt hexacarbonyl alkyne complexes derived from aspirin 21, from diphenyl acetylene 22, and from 2-propyn-l-ol have been studied on various cell lines, including... 

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