tert-butyldimethyl<((E)-4-methyl-1-pentenyl)oxy>silane | 135457-32-8

• 分子结构分类: 有机化合物 - 有机金属化合物 - 有机类金属化合物
• 英文名称: tert-butyldimethyl<((E)-4-methyl-1-pentenyl)oxy>silane
• 英文别名: tert-butyl-dimethyl-[(E)-4-methylpent-1-enoxy]silane
• CAS: 135457-32-8
• 化学式: C₁₂H₂₆OSi
• 分子量: 214.423
• InChiKey: OZJIIEZPZQTLCP-CSKARUKUSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  4.57
• 重原子数：
  14
• 可旋转键数：
  5
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.83
• 拓扑面积：
  9.2
• 氢给体数：
  0
• 氢受体数：
  1

反应信息

• 作为产物：
  描述：

  2-碘代丙烷 、 叔丁基二甲基氯硅烷 、 丙烯醛 生成 tert-butyldimethyl<((E)-4-methyl-1-pentenyl)oxy>silane
  参考文献：
  名称：

  A practical reversed-polarity alternative to organocuprate conjugate addition chemistry. Halocarbon coupling reactions of enal- and enone-derived allylnickel reagents

  摘要：

  A direct method for the conversion of conjugated enals and enones into [1-[(trialkylsilyl)oxy]allyl]nickel(II) chloride complexes is described. Reaction of R1CH = CR2CHO (R1 = H, Me, Ph; R2 = H and R1 = H; R2 = Me) with Ni(COD)2 (COD = 1,5-cyclooctadiene) and ClSiMe2R3 (R3 = Me or t-Bu) affords bis[[1,2,3-eta-3-1-[(trialkylsilyl)oxy]-2-propenyl](mu-chloro)nickel(II)] complexes 1a-f as burgundy-red crystalline solids in high to excellent yields (86-98%). The X-ray crystal structure of 1c confirms the eta-3-bonding mode for the allyl ligand and provides evidence of significant overlap of oxygen lone pair electron density with the allyl pi-system. Reaction of 3-buten-2-one with Ni(COD)2 and Me3SiCl similarly affords bis[[1,2,3-eta-3-1-methyl-1-[(trimethylsilyl)oxy]-2-propenyl](mu-chloro)nickel(II)] (1g) in 72% yield, while the corresponding 2-cyclopentenone reaction fails, giving rise to a nickel metal mirror. The latter reaction does, however, succeed when conducted in the presence of pyridine, giving bis(pyridine)(chloro)[1,2,3-eta-3-1-[(tert-butyldimethylsilyl)oxy]-2-cyclopentenyl]nickel(II) complex (1h) in 95% yield. Irradiation of 1e (R1 = R2 = H; R3 = t-Bu) in the presence of 2-iodopropane affords tert-butyldimethylsilyl (E)-enol ether 2a in 78% yield (E:Z = 10:1). Similar results are observed with [1-(trialkylsilyl)oxy]allyl]nickel(II) chloride complexes generated in situ from propenal, 2-methylpropenal, 2-butenal, 2-methyl-2-butenal, hexenal, and 3-buten-2-one, in coupling reactions with 1-iodobutane, 2-iodopropane, 1-bromoethene, 2-bromopropene, bromobenzene, o-bromobenzaldehyde, and isobutyryl chloride, affording the corresponding silyl (E)-enol ethers in 60-78% isolated, purified yield, based on Ni(1,5-COD)2. High C(3) regioselectivities (> 20:1) are observed for all of the C(3)-unsubstituted enals, while lower regioselectivities, in the range of 4-6:1 before purification, are observed for the C(3)-substituted enals; regioisomerically pure materials are obtained upon chromatography. Moderate to high E:Z stereoselectivities (E:Z = 4-15:1 before purification; E:Z = 20-50:1 after chromatography) are observed in all cases, save the reaction of isobutyryl chloride with 1e and the reaction of the 3-buten-2-one-derived allylnickel complex with 2-bromopropene, both of which give 1:1 E:Z ratios. In a more convenient, economical, and general variant, Ni(COD)2 is generated in situ via the sodium metal reduction of NiCl2(pyridine)4 (in turn prepared from NiCl2(H2O)6) in the presence of cyclooctadiene and reacted with the enal or enone in the presence of ClSiMe2R3 to afford the [1-[(trialkylsilyl)oxy]allyl](chloro)(pyridine)nickel(II) complex, which is treated with the halocarbon and irradiated to afford the usual silyl enol ether products. Yields of 63-84%, based on enal or enone, were observed in reactions with propenal, (E)-2-hexenal, 2-cyclopentenone, and 2-cyclohexenone in reactions with bromoethene, bromobenzene, and 1-iodobutane using this procedure.

  DOI：

  10.1021/ja00016a037

文献信息

• A practical reversed-polarity alternative to organocuprate conjugate addition chemistry. Halocarbon coupling reactions of enal- and enone-derived allylnickel reagents
  作者：John R. Johnson、Paul S. Tully、Peter B. Mackenzie、Michal Sabat

  DOI：10.1021/ja00016a037

  日期：1991.7

  A direct method for the conversion of conjugated enals and enones into [1-[(trialkylsilyl)oxy]allyl]nickel(II) chloride complexes is described. Reaction of R1CH = CR2CHO (R1 = H, Me, Ph; R2 = H and R1 = H; R2 = Me) with Ni(COD)2 (COD = 1,5-cyclooctadiene) and ClSiMe2R3 (R3 = Me or t-Bu) affords bis[[1,2,3-eta-3-1-[(trialkylsilyl)oxy]-2-propenyl](mu-chloro)nickel(II)] complexes 1a-f as burgundy-red crystalline solids in high to excellent yields (86-98%). The X-ray crystal structure of 1c confirms the eta-3-bonding mode for the allyl ligand and provides evidence of significant overlap of oxygen lone pair electron density with the allyl pi-system. Reaction of 3-buten-2-one with Ni(COD)2 and Me3SiCl similarly affords bis[[1,2,3-eta-3-1-methyl-1-[(trimethylsilyl)oxy]-2-propenyl](mu-chloro)nickel(II)] (1g) in 72% yield, while the corresponding 2-cyclopentenone reaction fails, giving rise to a nickel metal mirror. The latter reaction does, however, succeed when conducted in the presence of pyridine, giving bis(pyridine)(chloro)[1,2,3-eta-3-1-[(tert-butyldimethylsilyl)oxy]-2-cyclopentenyl]nickel(II) complex (1h) in 95% yield. Irradiation of 1e (R1 = R2 = H; R3 = t-Bu) in the presence of 2-iodopropane affords tert-butyldimethylsilyl (E)-enol ether 2a in 78% yield (E:Z = 10:1). Similar results are observed with [1-(trialkylsilyl)oxy]allyl]nickel(II) chloride complexes generated in situ from propenal, 2-methylpropenal, 2-butenal, 2-methyl-2-butenal, hexenal, and 3-buten-2-one, in coupling reactions with 1-iodobutane, 2-iodopropane, 1-bromoethene, 2-bromopropene, bromobenzene, o-bromobenzaldehyde, and isobutyryl chloride, affording the corresponding silyl (E)-enol ethers in 60-78% isolated, purified yield, based on Ni(1,5-COD)2. High C(3) regioselectivities (> 20:1) are observed for all of the C(3)-unsubstituted enals, while lower regioselectivities, in the range of 4-6:1 before purification, are observed for the C(3)-substituted enals; regioisomerically pure materials are obtained upon chromatography. Moderate to high E:Z stereoselectivities (E:Z = 4-15:1 before purification; E:Z = 20-50:1 after chromatography) are observed in all cases, save the reaction of isobutyryl chloride with 1e and the reaction of the 3-buten-2-one-derived allylnickel complex with 2-bromopropene, both of which give 1:1 E:Z ratios. In a more convenient, economical, and general variant, Ni(COD)2 is generated in situ via the sodium metal reduction of NiCl2(pyridine)4 (in turn prepared from NiCl2(H2O)6) in the presence of cyclooctadiene and reacted with the enal or enone in the presence of ClSiMe2R3 to afford the [1-[(trialkylsilyl)oxy]allyl](chloro)(pyridine)nickel(II) complex, which is treated with the halocarbon and irradiated to afford the usual silyl enol ether products. Yields of 63-84%, based on enal or enone, were observed in reactions with propenal, (E)-2-hexenal, 2-cyclopentenone, and 2-cyclohexenone in reactions with bromoethene, bromobenzene, and 1-iodobutane using this procedure.