| 130220-49-4

• 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
• CAS: 130220-49-4
• 化学式: C₁₂H₂₄Si
• 分子量: 196.408
• InChiKey: YNFUUQAPTGGHPB-PGGWCAKNSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  4.41
• 重原子数：
  13.0
• 可旋转键数：
  2.0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.67
• 拓扑面积：
  0.0
• 氢给体数：
  0.0
• 氢受体数：
  0.0

反应信息

• 作为产物：
  描述：

  在 H₂O 作用下， 以 乙醚 、 丙酮 为溶剂， 生成
  参考文献：
  名称：

  Cross-coupling reactions of d2 tantalum alkyne complexes: selective 1,3-diene syntheses and their relevance to alkyne cyclization chemistry

  摘要：

  Ta(DIPP)3Cl2(OEt2) (DIPP = 2,6-diisopropylphenoxide) can be reduced by two electrons in the presence of the bulky alkynes PhC = CPh and Me3SiC = CMe to provide the pale yellow adducts (DIPP)3Ta-(PhC = CPh) (1) and (DIPP)3Ta(Me3SiC = CMe) (2). The reduction of Ta(DIPP)3Cl2(OEt2) in the presence of smaller internal alkynes (viz. EtC = CEt) or the terminal alkynes Me3SiC = CH or Me3CC = CH affords the metallacyclopentadienes (DIPP)3Ta-activated-(CEt = CEtCet = CEt) (3) or (DIPP)3Ta-activated-(CR = CHCR = CH) (4, R = SiMe3; 5, R = CMe3) directly. The molecular structure of the PhC = CPh adduct 1 is approximately tetrahedral (L-Ta-L angles average 109.4-degrees) and features very short Ta-C(alkyne) distances (2.070 (3) and 2.076 (3) angstrom, respectively) and an elongated "C = C" bond (1.346 (5) angstrom), which indicate a strongly bound and substantially reduced alkyne ligand. The molecular structure of metallacycle 3 reveals a trigonal bipyramidal geometry (L(ax)-Ta-L(ax) = 164.9 (3)-degrees) with the metallacyclic alpha carbons occupying one axial and one equatorial site. The alkyne complex (DIPP)3Ta(PhC = CPh) (1) reacts with MeC = CMe, EtC = CEt, Me3CC = CH, Me3SiC = CH, or PhC = CH to afford high yields of the metallacyclization products (DIPP)3Ta-activated-a(CPh = CPhCMe = CMe) (6), (DIPP)3Ta(CPh = CPhCEt = CEt) (7), (DIPP)3 Ta-activated (CPh = CPhCH = CCMe3) (8), (DIPP)3Ta-activated-(CPh = CPh CPhCH=?? = CSiMe3) (9), and (DIPP)3 Ta-acitvated-(CPh = CPhCH = CPh) (10), respectively, while 1,7-octadiyne HC = C(CH2)4C = CH reacts with 2 equiv of (DIPP)3Ta(PhC = CPh) to provide the unusual bimetallic complex (DIPP)3T-activated-a(CPh = CPhCH = C(CH2)4- C = CHCPh = PhC)Ta(DIPP)3 (11). The alkyne adduct (DIPP)3 Ta(Me3SiC = CMe) (2) also engages in metallacyclization chemistry as it reacts with MeC = CMe to afford (DIPP)3T-activated-a(CMe = CSiMe3CMe = CMe) (12), with PhC = CH to provide (DIPP)3T-activated-a(CSiMe3 = CMeCPh = CH) (13), and with Me3CC = CH to afford (DIPP)3T-activated-a(CCMe3 = CHCSiMe3 = CMe) (14). All of the metallacyclopentadiene complexes can be hydrolyzedwith H2O/ acetone solutions to afford the corresponding 1,3-dienes in essentially quantitative yields. However, iodination of metallacycles 6, 7, and 13 does not yield the expected 1,4-diiodo-1,3-dienes but rather the ring-opened monoiodinated butadienyl compounds (DIPP)3(I)TaCPh = CPhCMe = CMe(I) (15), (DIPP)3(I)TaCPh = CPhCEt = CEt(I) (16), and (DIPP)3(I)TaCSiMe3 = CMeCPh = CH(I) (17), respectively. The subsequent hydrolysis of compounds 15-17 provides the corresponding 1-iodo-1,3-dienes.

  DOI：

  10.1021/om00047a038