Takasago International Corporation

Takasago A catalytic process for the enantioselective isomerization of allylic amines. The catalyst is a chiral rhodium complex. Used in the manufacture of (-)menthol. Named after Takasago International Corporation, the Japanese company which commercialized the process in 1983. 

Isomerization of allylic amines is another example of the application of the BINAP complex. Rh BINAP complex catalyzes the isomerization of N,N-diethylnerylamine 40 generated from myrcene 39 with 76-96% optical yield. Compound (R)-citronellal (R)-42. prepared through hydrolysis of (R)-41, is then cyclized by zinc bromide treatment.49 Catalytic hydrogenation then completes the synthesis of (—)-menthol. This enantioselective catalysis allows the annual production of about 1500 tons of menthol and other terpenic substances by Takasago International Corporation.50... 

Financial resources for the colloquium were provided by the Academy and supplemented by contributions from a number of industries (American Cyana-mid Company, E. I. DuPont de Nemours Co., Givaudan-Roure Corporation, Merck Co., Monsanto, Rohm and Haas Company, Schering-Plough Research Institute, Sterling-Winthrop Inc., Syntex, Takasago International Corporation, Zeneca Inc.), to which we are much indebted. 

Scheme 7 lists some terpenic compounds that are commercially produced by Takasago International Corporation (9). Most of the (R)-citro-nellal and isopulegol that is prepared in this way is converted to (—)-menthol. 

Takasago International Corporation, Nissay Aroma Square I8F, 37-1, Kamata 5-chome Ohta-ku, Tokyo, Japan 144-8721... 

Allylic double bonds can be isomerized by some transition metal complexes. Isomerization of alkyl allyl ethers 480 to vinyl ethers 481 is catalysed by Pd on carbon [205] and the Wilkinson complex [206], and the vinyl ethers are hydrolysed to aldehydes. Isomerization of the allylic amines to enamines is catalysed by Rh complexes [207]. The asymmetric isomerization of A jV-diethylgeranylamine (483), catalysed by Rh-(5)-BINAP (XXXI) complex to produce the (f )-enaminc 484 with high optical purity, has been achieved with a 300 000 turnover of the Rh catalyst, and citronellal (485) with nearly 100% ee is obtained by the hydrolysis of the enamine 484 [208]. Now optically pure /-menthol (486) is commerically produced in five steps from myrcene (482) via citronellal (485) by Takasago International Corporation. This is the largest industrial process of asymmetric synthesis in the world [209]. The following stereochemical corelation between the stereochemistries of the chiral Rh catalysts, diethylgeranylamine (483), diethylnerylamine (487) and the (R)- and (5)-enamines 484... 

Takasago International Corporation (USA), 100 Green Street, Teterboro, NJ 07806... 

The use of chiral rhodium-BINAP complexes for the asymmetric isomerization of alkenes has been utilized in the industrial synthesis of menthol by Ryoji Noyori (winner of the 2001 Nobel Prize in Chemistry). This synthetic method was industrialized by Takasago International Corporation and provides (—)-menthol to pharmaceutical and food companies worldwide. In this case the catalyst [(S-BINAP)-Rh(COD)] or [(S-BINAP)2-RuC104 ] is used for the asymmetric isomerization of diethylgeranylamine (1.62) to 3-(R)-citronellalenamine (1.63) (Scheme 1.13). 

Scheme 1.13 Asymmetric synthesis of menthol by Takasago International Corporation...

A landmark process using a cationic Rh complex with a BINAP ligand is working at Takasago International Corporation, Japan, on up to a nine-ton scale. 

Takasago International Corporation, 4 Volvo Drive, Rockleigh, NJ 07647... 

One of Noyori s most remarkable achievements is a commercial synthesis of (-)-menthol 51 used since 1983 by the Takasago International Corporation on a scale of thousands of tonnes a year. This and related processes are discussed in detail by S. Akutagawa and K. Tani in chapter 3 of Ojima s Catalytic Asymmetric Synthesis. The process is summarised here ... 

Susumu Akutagawa Takasago International Corporation Nissay Aroma Square 5-37-1 Kamata Ohta-ku Tokyo 144-8721, Japan e-mail akutag bni.co.jp... 

Another sulfonated derivative of BINAP was mentioned in a patent of Takasago International Corporation [8]. Cationic complexes of ruthenium and or iridium with this ligand - sulfonated on the 5- and 5 -positions of the naphthyl rings - are claimed to affect asymmetric hydrogenation of olefins, ketones, and imines. 

The symposium and book would not have been possible without the financial assistance of Ajinomoto Company, Inc. Hasegawa Company, Ltd. Kirin Brewery Company, Ltd. Ogawa Company, Ltd. and Takasago International Corporation. We are grateful for their generous contributions. 

T. Hasegawa Company, Limited, 167 Takasago International Corporation, 188 Technische Universitat Miinchen,... 

The story of the development of the lab-scale reaction into a 1000 ton per year process has been told in several reviews, and detailed information on the mechanism of the reaction has been published previously. The initially formed enamine (12.02) is converted into citronellal (12.03) by hydrolysis, with subsequent cyclisation to isopulegol (12.04) and reduction to menthol (12.05). The whole process is performed by Takasago International Corporation, and represents the biggest application (so far) of an enantioselective reaction catalysed by a transition metal complex. Interestingly, the alternative geometry of starting material (the (Z)-isomer) affords the opposite enantiomer of product. 

Y. Hori, T. Nishishita, and A. Yamaguchi, Process for producing poly-(3-hydroxybutyric acid), US Patent 5430125, assigned to Takasago International Corporation (Tokyo, JP), July 4,1995. 

From Ottinger, H., T. Soldo, T. Hoffmann, J. Agric. Food Chem., 2001(49) p. 5383. With permission. From Kenmochi, H., T. Akiyama, Y. Yuasa, T. Kobayashi, A. Tachikawa, Method for producing para-menthane-3,8-diol. United States Patent 5959161, 1999, Takasago International Corporation. With permission. 

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