| 143681-81-6

• CAS: 143681-81-6
• 化学式: C₃₇H₃₆MoO₈P₂
• 分子量: 766.576
• InChiKey: KYXVOAGXOJELAB-BNASEXRFSA-N

反应信息

• 作为产物：
  描述：

  (R,R)-2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis({2-methoxyphenyl}phenylphosphino)butane 、 molybdenum hexacarbonyl 在 NaBH₄ 作用下， 以 乙醇 为溶剂， 以13%的产率得到
  参考文献：
  名称：

  Stereochemically matched (and mismatched) bisphosphine ligands: DIOP-DIPAMP hybrids

  摘要：

  The three diastereomers of (RR)-2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis([2-methoxyphenyl]-phenylphosphino)butane (1) and of (RR)-2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis([2-(dimethylamino)phenyl]phenylphosphino)butane (2) have been prepared and isolated. Advanced intermediates in the preparation and isolation of diastereomers of (R,R)-2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis([2,6-dimethoxyphenyl]phenylphosphino)butane (3) are also described. Absolute configurations of four of the chiral phosphine ligands were determined via single-crystal X-ray diffraction studies of molybdenum tetracarbonyl derivatives (R(p),R(p))-7, (R(p),R(p))-8, and (S(p),S(p))-8); this facilitated assignments of absolute configurations for all the isomers of ligands 1-3. These bisphosphine ligands are rare insofar as they have chiral phosphorus centers supported on an asymmetric carbon framework. Several reactions were performed to test for "cooperativity" between chiral centers m these ligands with respect to asymmetric induction in transition-metal-catalyzed processes. Matching and mismatching effects were observed, but there are some irregular trends in the data. The enantioselectivities obtained were moderate but greater than that for the parent ligand DIOP in some cases. The o-dimethylamino functionality of ligands 2 may play an active role m the coordination of these isomeric bisphosphine ligands. Trends and factors influencing the performance of ligands 1-3 in asymmetric catalysis are discussed. Crystal data for the compounds analyzed via X-ray diffraction are as follows. (R(p),R(p))-6: monoclinic, space group P2, (No. 4), a = 11.621 (3) angstrom, b = 10.676 (2) angstrom, c = 14.850 (2) angstrom, beta = 101.59 (2)-degrees, V = 1804.8 (6) angstrom3, Z = 2, R = 0.029. (F(p),R(p))-7.0.5CH2Cl2.. monoclinic, space group P21 (No.4), a = 11.013 (6) angstrom, b = 21.134 (5) angstrom, c = 18.555 (6) angstrom, beta = 101.32 (3)-degrees, V = 4235 (2) angstrom3, Z = 4, R = 0.111. (R(p),R(p))-8: triclinic, space group P1 (No. 1), a = 11.64 (1) angstrom, b = 16.05 (1) angstrom, c = 10.760 (7) angstrom, alpha = 94.06 (6)-degrees, beta = 97.05 (6)-degrees, gamma = 97.10 (7)-degrees, V = 1973 (5) angstrom3, Z = 2, R = 0.098. (S(p),S(p))-8: orthorhombic, space group P2(1)2(1)2(1) (No. 19), a = 14.007 (3) angstrom, b = 27.419 (8) angstrom, c = 10.394 (3) angstrom, V = 3992 (2) angstrom3, Z = 4, R = 0.052.

  DOI：

  10.1021/om00059a023