25462-41-3

Upstream product

• 19157-51-8 ethyl 2-ethoxycarbonyl-2-methyl-4-pentynoate 
• 135460-76-3 2-methyl-2-(2-propynyl)malonic acid dimethyl ester 
• 95124-07-5 dimethyl (prop-2-yn-1-yl)malonate 

Downstream Products

• 932699-73-5 C₃₉H₄₈O₂Si₂ 
• 1027419-14-2 C₄₃H₅₅IO₂Si₂ 
• 932699-75-7 1-(tert-butyl-dimethyl-silanyloxy)-8-(tert-butyl-diphenyl-silanyloxy)-7-(tert-butyl-diphenyl-silanyloxymethyl)-7-methyl-oct-4-yn-3-one 
• 932699-76-8 1-(tert-butyl-dimethyl-silanyloxy)-8-(tert-butyl-diphenyl-silanyloxy)-7-(tert-butyl-diphenyl-silanyloxymethyl)-7-methyl-oct-4-yn-3-ol 
• 502926-59-2 C₃₁H₃₀P₂ 
• 502926-58-1 (CH₃)3SiCCCH₂C(CH₃)(CH₂P(C₆H₅)2)2 

Relevant academic research and scientific papers

(Pentamethylcyclopentadienyl)iridium dichloride dimer {[IrCp*Cl 2]2}: A novel efficient catalyst for the cycloisomerizations of homopropargylic diols and N-tethered enynes

(Pentamethylcyclopentadienyl)iridium dichloride dimer {[IrCp*Cl 2]2}-catalyzed hydroalkoxylation of bis-homopropargylic alcohols provides an efficient access to dioxabicyclo[2.2.1]ketals. The cycloisomerizations proceed under mild conditions, with low catalytic loadings and short reaction times. This new protocol involving an Ir(III) catalyst also promoted the cycloisomerization of nitrogen-tethered 1,6-enynes to give azabicyclo[4.1.0]heptenes, enhancing the synthetic potential of our method. Copyright

Didentate phosphine ligands with alkenyl and alkynyl linker units as building blocks for dendrimer fixation

Using diethyl-2-methylmalonate as a starting material, the two diphosphines HC≡CCH2C(CH3)(CH2PPh2) 2 (7) and H2C=CHCH2C(CH3)(CH2PPh 2)2 (13), containing alkynyl and alkenyl unit in the ligand backbone were prepared in multistep syntheses. These two ligands were employed in the synthesis of [{(CH3)3SiC≡CCH2C(CH3) (CH2PPh2)2}PdCl2] (8) and [{(CH3)3SiC≡CCH2C(CH3) (CH2PPh2)2}PtCl2] (9) as well as [{H2C=CHCH2C(CH3)(CH2PPh 2)2}PdI2] (14b), all of which were characterized by X-ray diffraction. Reaction of Si[(CH2)3SiMe2Cl]4 (= "G[0]-[Cl]4") with four molar equivalents of the in situ lithiated alkynyl diphosphine 7 cleanly yielded the four-fold functionalized derivative G[0]-[C≡CCH2C(CH3)(CH2PPh 2)2]4 (15) which was converted to the metallated derivative G[0]-[C≡CCH2C(CH3)(CH2PPh 2)2PdCl2]4 (16). Since the fixation of the alkenyl-functionalized diphosphine ligand 13 to the SiH-silane Si[(CH2)3SiMe2H]4 (= "G[0]-[H]4") by Pt-catalyzed hydrosilation proved to be unsuccessful due to the negative interference of the phosphine with Karstedt's catalyst, the chloro-substituted precursor of 13, H2C=CHCH2C(CH3)(CH2Cl) 2 (12) was used. Hydrosilation of G[0]-[H]4 with four molar equivalents of 12 readily gave the functionalized dendrimer G[0]-[CH2CH2CH2C(CH3)(CH 2Cl)2]4 (17) which was then reacted with eight equivalents of LiPPh2 to yield the phosphinated derivative G[0]-[CH2CH2CH2C(CH3)(CH 2PPh2)2]4 (18).