Lanthagen

Kojundo Chemical Laboratory has studied, developed, manufactured, and sold metal alkoxides for a long time, and got many experience and know-how. Metal alkoxides are generally used for a sol-gel process and a MOCVD method, which makes metal oxide thin films. Nowadays, lanthanoid alkoxides such as lanthanum tri-isopropoxide are known as an ingredient of asymmetric catalyst.

Catalytic activity of Kojundo Chemical Laboratory’s lanthanoid alkoxides is highly valued by many customers. We have developed an evaluation method for the catalytic activity of lanthanoid alkoxides under the guidance of Prof. Shibasaki at Graduate School of Pharmaceutical Sciences, The University of Tokyo (patent pending). Every production lot is evaluated by this method and only qualified product is provided as named "Lanthagen®
Here, we would like to introduce "Lanthagen®; to customers.


Outline of our evaluation method

Ln-BINOL catalyst consisting of lanthanoid alkoxides and BINOL is prepared and used for epoxidation of chalcone. Catalytic activity is expressed in yield and enantiomeric excess of the epoxidation. The reaction for this evaluation is conducted at a lower temperature and in a shorter reaction time, without additives such as Ph3As=O. Then determined values are generally lower than that shown in past references.

触媒活性評価法の概要

Representative examples1,2

Nitro-aldol reaction3
Nitro-aldol reaction
Michael reaction4
Michael reaction
Epoxidation reaction of enone5, 6
Epoxidation reaction of enone
Epoxidation reaction of α.β-unsaturated N-acylimidazole7
Epoxidation reaction of α.β-unsaturated N-acylimidazole
Epoxidation reaction of α.β-unsaturated amide8
Epoxidation reaction of α.β-unsaturated amide
Cyanosilylation reaction of ketone9, 10
Cyanosilylation reaction of ketone
Hydrophosphonylation reaction11
Hydrophosphonylation reaction
References:(1)Review: Angew. Chem. Int. Ed. Engl. 1997. 36. 1236. (2)Review: Chem. Rev. 2002. 102. 2187. (3)J. Am. Chem. Soc. 1993. 115. 10372. (4)J. Am. Chem. Soc. 2000. 122. 6506. (5)J. Am. Chem. Soc. 1997. 119. 2329. (6)J. Am.Chem. Soc. 2001. 123. 2725. (7)J. Am. Chem. Soc. 2001. 123. 9474. (8)J. Am. Chem. Soc. 2002. 124. 14544. (9)J. Am.Chem. Soc. 2001. 123. 9908. (10)Tetrahedron Lett. 2002. 43. 8467. (11)J. Am. Chem. Soc. 1998. 120. 3089. Other examples: (12)J. Am. Chem. Soc. 2001. 123. 2466. (13)Angew. Chem. Int. Ed. 1999. 38. 3504. (14)Angew. Chem. Int. Ed.2002. 41. 3636.
Those data are by courtesy of Prof. Shibasaki at Graduate School of Pharmaceutical Sciences, The University of Tokyo.


A list of Lanthanoid alkoxide for catalyst

* 1. Degree of association was calculated from molecular weight measurement by using a benzene cryoscopic method.
* 2. Solubility is an amount of dissolved substance in 1 liter of the solution at room temperature. (typical data)
* 3. Figure's of Metal content and Impurity are typical data.
Code No. LAR04GB PRR02GB SMR02GB GDR02GB YBR02GB YYR04GB
Chemical formula La(O-i-C3H7)3 Pr(O-i-C3H7)3 Sm(O-i-C3H7)3 Gd(O-i-C3H7)3 Yb(O-i-C3H7)3 Y(O-i-C3H7)3
Name Lanthanum
tri-isopropoxide
Praseodymium
tri-isopropoxide
Samarium
tri-isopropoxide
Gadolinium
tri-isopropoxide
Ytterbium
tri-isopropoxide
Yttrium
tri-isopropoxide
CAS No. 19446-52-7 19236-14-7 3504-40-3 14532-05-9 6742-69-4 2172-12-5
Molecular weight 316.2 318.2 327.6 334.5 350.3 266.2
Physical form White solid Light green solid Yellow-orange solid White solid White solid White solid
Association*1 - - - - - 4.0
Solubility
(g/L)**2
THF 320 300 470 250 310 240
Toluene 200 220 280 290 270 200
Hexane 270 310 470 250 310 240
IPA 80 50 40 30 180 20
Quantity of rare earth metal*3(%) 43.9 46.0 48.3 50.0 47.6 37.3
Impurities*3(%) Al <0.01 <0.01 <0.01 <0.01 <0.01 0.02
Ca <0.01 0.06 <0.01 <0.01 <0.01 <0.01
Fe <0.01 <0.01 <0.01 <0.01 <0.01 <0.01
Si <0.01 <0.01 0.03 0.03 <0.02 0.03
Na 0.30 0.10 0.13 0.52 <0.01 <0.01
Cl 0.68 1.0 0.47 0.26 0.02 0.06
Catalytic
activity
yield(%) ≥55 ≥63 ≥54 ≥82 ≥41 ≥84
ee(%ee) ≥70 ≥51 ≥56 ≥51 ≥62 ≥15

Handling Precautions

  1. Product is contained in a glass ampoule filled with inert gas.
  2. If metal alkoxide contact with even slight moisture in air, it will decompose and lose catalytic activity. Please treat in a glove box or a glove bag filled with dry inert gas.
  3. Please use up immediately, once open an ampoule.
  4. Please use a solvent dehydrated enough, for dissolving a product.

Ordering

  1. To order lanthanoid alkoxide for catalysts shown in this catalog, please specify "Lanthagen."
  2. Please order by fax or phone, clearly stating the code number and product name from the catalog, and the quantity.
  3. Two types of 3g and 50g in an ampoule are always available. If you need larger quantities, you can request to us.
  4. We deal in lanthanoid alkoxides such as Ce, Nd, Eu, Dy, Er alkoxides as well as "Lanthagen®". In addition, we deal in Al, Zr, Hf, and other alkoxides. For particulars, apply to us.