Propargyl

About: Propargyl is a research topic. Over the lifetime, 5302 publications have been published within this topic receiving 85038 citations.

Preparation, metallation and alkylation of allenyl ethers

Abstract: Propargyl ethers HCCCH2OR [R = alkyl or-CH(CH8)(OC2H5)] have been isomerized with good yields into the corresponding allenyl ethers CH2CCHOR by warming with potassium tert.-butoxide at 70°. These allenyl ethers can be metallated with butyllithium in ether or alkali amides in liquid ammonia. In ether, subsequent alkylation with alkyl halides R′Hal affords α-substituted allenyl ethers CH2CC(R′)OR. Alkylation in liquid ammonia produces a mixture of this same compound and the γ-substituted product R′CHCCHOR. In both cases reasonable yields are obtained. Sodamide and potassium amide quickly convert allenyl ethers CH2CCHOR into metallated propargyl ethers MCC-CH2OR (M = Na or K). If alkylation is not performed almost simultaneously with the metallation with sodamide or potassium amide, the only alkylation product obtained is R′CCCH2OR.

Highly Efficient “Click” Functionalization of Poly(3-azidopropyl methacrylate) Prepared by ATRP

Abstract: To prepare polymers with pendant functionality capable of participating in highly efficient CuI-catalyzed 1,3-dipolar cycloaddition of azide and alkynes, monomers with acetylene or azido groups were polymerized via controlled radical polymerization Atom transfer radical polymerization (ATRP) of propargyl methacrylate (PgMA) resulted in high polydispersities (Mw/Mn > 3), multimodal molecular weight distributions, and cross-linked networks at moderate to high conversion The poor results obtained with this monomer were presumably due to addition of the propagating radicals to the acetylene group, transfer reactions, and/or interference with the catalyst A novel monomer, 3-azidopropyl methacrylate (AzPMA), was polymerized via ATRP with good control of the polymer molecular weight distribution and retention of chain functionality Poly(3-azidopropyl methacrylate) was coupled with propargyl alcohol, propargyl triphenylphosphonium bromide, propargyl 2-bromoisobutyrate, and 4-pentynoic acid via a highly effici

Gold(I)-catalyzed stereoselective olefin cyclopropanation.

Abstract: A triphenylphosphinegold(I)-catalyzed cyclopropanation of olefins using propargyl esters as gold(I)−carbene precursors is reported. This reaction provided the basis for the use of a DTBM-SEGPHOS gold(I) complex as a catalyst in the enantioselective (up to 94% ee) preparation of vinyl cyclopropanes with high cis-selectivity.

Novel benzoxazine monomers containing p-phenyl propargyl ether: Polymerization of monomers and properties of polybenzoxazines

Abstract: Novel benzoxazine monomers containing arylpropargyl ether were prepared, and highly thermally stable polybenzoxazines were obtained by the thermal cure of the monomers. One monomer is a monofunctional benzoxazine, 4-propargyloxyphenyl- 3,4-dihydro-2H-1,3-benzoxazine (P-appe), and the other is a bifunctional benzoxazine, bis(4-propargyloxyphenyl-3,4-dihydro-2H-1,3-benzoxazinyl)isopropane (B-appe). The chemical structures of these novel monomers were confirmed by IR and 1H NMR. The cure behavior of the monomers, P-appe and B-appe, and the properties of the resulting polymers were studied in comparison with 4-phenyl-3,4-dihydro-2H-1,3-benzoxazine (P-a) and bis(4-phenyl-3,4-dihydro-2H-1,3-benzoxazinyl)isopropane (B-a) as typical benzoxazine monomers without propargyl groups. DSC cure of both P-appe and B-appe showed a single exotherm corresponding to the ring-opening polymerization of oxazine ring and cross-linking of arylpropargyl ether group at almost the same temperature range as P-a and B-a. The Tg values...