Disilylation of conjugated dienes. Configuration of diene anion radicals annd dianions

Weyenberg, Donald R.; Toporcer, Louis H.; Nelson, L.

doi:10.1021/jo01269a060

Cited by 90 publications

(14 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This rapid and exclusive cyclization, in the absence of solvent, indicates that monomer 2 prefers to adopt the conformation predicted by the gem-dimethyl or Thorpe-Ingold effect22-placing the olefins in close proximity. Cyclic compound 3 has been prepared previously by Weyenberg et al,23 through a different route, and the compound's refractive index and boiling point were reported.…”

Section: Resultsmentioning

confidence: 99%

Acyclic diene metathesis (ADMET) polymerization. Design and synthesis of unsaturated poly(carbosiloxanes)

Smith¹,

Wagener²

1993

Macromolecules

View full text Add to dashboard Cite

The synthesis of unsaturated poly(carbosiloxane)s, a new class of siloxane polymers possessing a perfectly alternating siloxane and alkenylene main chain, is presented. 1,5-Bis(allyl)-1,1,3,3,5,5hexamethyltrisiloxane (4), l,3-bis(4-pentenyl)tetramethyldisiloxane (6), 1,1,3,, and telechelic a,a)-di-4-pentenylpoly(l,l,3,3-tetramethyldisiloxanylpentylene) (10) undergo acyclic diene metathesis (ADMET) polymerization catalyzed by [(CF.ihCHsCOLUV-^.e-CeH.ri-Pr2)Mo=CHC(CH:i)2Ph (1). These polymerizations, which are performed under bulk conditions and at low temperatures, continuously release ethylene to give poly(l,l,3,3,5,5-hexamethyltrisiloxanyl-2-butenylene) (5), poly(1,1,3,3-tetramethyldisiloxanyl-4-octenylene) (7), poly(1,1,3,3-tetramethyldisiloxanyl-p-phenylenel,l,3,3-tetramethyldisiloxanyl-2-butenylene) (9), and poly(l,1,3,3-tetramethyldisiloxanylpentylene-co-l,1,3,3tetramethyldisiloxanyl-4-octenylene) (11), respectively. Bis(vinyl)tetramethyldisiloxane fails to homopolymerize under ADMET conditions, and bis(allyl)tetramethyldisiloxane (2) releases ethylene when catalyzed by 1 in the absence of solvent, to give, exclusively, the ring-closed product, 1,1,3,3-tetramethyldisiloxacyclohept-5-ene (3). Extending the methylene units or the siloxane linkage in the monomer results in facile ADMET polycondensation, in essentially quantitative conversions, affording well-defined, low-Tg, linear polymers with known vinylic end groups. The polymerizations are void of competing reactions except when back-biting reactions are favorable. Polymer 5 undergoes back-biting to generate the nine-membered cyclic silaoxalkene 13, when active polymer is diluted or, to a lesser extent, when in the bulk. All monomers and polymers were characterized by infrared spectroscopy and , 13C, and 29Si NMR spectroscopy. Number average molecular weights were determined by gel permeation chromatography and quantitative 13C NMR end group analysis when possible. Synthesis, characterization, thermal analysis, and the current scope of this polymerization are discussed.

show abstract

Section: Resultsmentioning

confidence: 99%

Acyclic diene metathesis (ADMET) polymerization. Design and synthesis of unsaturated poly(carbosiloxanes)

Smith¹,

Wagener²

1993

Macromolecules

View full text Add to dashboard Cite

show abstract

“…However, it was demonstrated that the diene rather than the halosilane reacted initially with the alkali metal, and the role of the halosilane was merely to silylate a carbanion [33,34]. No firm evidence has been presented for the intermediacy of silylenes in these heterogeneous liquid phase reactions.…”

Section: H2c' 'Ch3 Ch2 Ch3mentioning

confidence: 99%

Tetramethyl-1-silacycloprop-2-ene: its characterization and reactions

Cornett¹

1980

View full text Add to dashboard Cite

“…(2,3-Dimethylbut-2-enyl)-n-butyldimethylsilane (VIII). *H NMR: -0.053 (s, 6 ), 0.46 (t, 2 H, J = 7.1 Hz), 0.86 (t, 3 H, J = 7.0 Hz), 1.27 (m, 4 ), 1.49 (s, 2 ), 1.56 (s, 3 ), 1.59 (s, 3 ), 1.61 (s, 3 H). GC/MS (relative intensity): m/e 200 (0.36), 199 (1.31), 198 (7.06; M-+), 183 (0.17; M -15+), 141 (1.01; M -57+), 125 (1.38), 117 (0.95), 116 (2.98), 115 (25.40; M -83+), 99 (4.51), 75 (1.74), 74 (4.10), 73 (48.17), 61 (3.52), 60 (7.53), 59 (100.00).…”

mentioning

confidence: 99%

Anionic ring-opening polymerization of 1,1,3-trimethyl-1-silacyclopent-3-ene. Effect of temperature on poly(1,1,3-trimethyl-1-sila-cis-pent-3-ene) microstructure

Park¹,

Manuel²,

Weber³

1990

Macromolecules

View full text Add to dashboard Cite

Disilylation of conjugated dienes. Configuration of diene anion radicals annd dianions

Cited by 90 publications

References 1 publication

Acyclic diene metathesis (ADMET) polymerization. Design and synthesis of unsaturated poly(carbosiloxanes)

Acyclic diene metathesis (ADMET) polymerization. Design and synthesis of unsaturated poly(carbosiloxanes)

Tetramethyl-1-silacycloprop-2-ene: its characterization and reactions

Anionic ring-opening polymerization of 1,1,3-trimethyl-1-silacyclopent-3-ene. Effect of temperature on poly(1,1,3-trimethyl-1-sila-cis-pent-3-ene) microstructure

Contact Info

Product

Resources

About