Mukaiyama reaction asymmetric synthesis

Tor a treatise on this subject, sec Morrison Asymmetric Synthesis, 5 vols. [vol. 4 co-cditcd by Scott] Academic Press New York, 1983-1985. For books, see N6gr4di Stereoselective Synthesis VCH New York, 1986 Eliel Olsuka Asymmetric Reactions and Processes in Chemistry American Chemical Society Washington, 1982 Morrison Mosher Asymmetric Organic Reactions Prentice-Hall Englewood Cliffs, NJ, 1971, paperback reprint, American Chemical Society Washington, 1976 Izumi Tai, Ref. I. For reviews, see Ward Chem. Soc. Rev. 1990, 19, 1-19 Whitesell Chem. Rev. 1989, 89, 1581-1590 Fujita Nagao Adv. Heterocycl. Chem. 1989, 45, 1-36 Kochetkov Belikov Russ. Chem. Rev. 1987, 56, 1045-1067 Oppolzer Tetrahedron 1987, 43, 1969-2004 Seebach Imwinkelried Weber Mod. Synth. Methods 1986, 4, 125-259 ApSimon Collier Tetrahedron 1986, 42, 5157-5254 Mukaiyama Asami Top. Curr. Chem. 1985, 127, 133-167 Martens Top. Curr. Chem. 1984, 125, 165-246 Duhamel Duhamel Launay Plaqucvcnt Bull. Soc.Chim. Fr. 1984,11-421-11-430 Mosher Morrison Science 1983,221, 1013-1019 Schollkopf Top. Curr. Chem. 

A catalytic asymmetric vinylogous Mukaiyama reaction between silyl dienolate 896 and aliphatic ketone 897 provides the 5,6-dihydropyran-2-one 898, a key intermediate during a formal synthesis of enantiopure taurospongin A (Equation 361) <2005JA7288>. 

A short asymmetric synthesis of the 2-ketocarbacepham (27) involving as the initial step for the preparation of the starting piperidone, a hetero Diels-Alder reaction of the benzylimine derived from the enantiomer of Gamer s aldehyde with Danishesky s diene, has been described <02JOC598>. The key cyclization step to form the bicyclic P-lactam system was achieved from a P-amino acid precursor using the Mukaiyama reagent, 2-chloro-A-methylpyridinium iodide. 

Silyl enol ethers react with aldehydes in the presence of chiral boranes or other additives " to give aldols with good asymmetric induction (see the Mukaiyama aldol reaction in 16-35). Chiral boron enolates have been used. Since both new stereogenic centers are formed enantioselectively, this kind of process is called double asymmetric synthesis Where both the enolate derivative and substrate were achiral, carrying out the reaction in the presence of an optically active boron compound ° or a diamine coordinated with a tin compound ° gives the aldol product with excellent enantioselectivity for one stereoisomer. Formation of the magnesium enolate anion of a chiral amide, adds to aldehydes to give the alcohol enantioselectively. 

SCHEME 13. 33 Mukaiyama s asymmetric aldol reactions total synthesis of D-ribose, 4-C-methyl-D-ribose and 6-deoxy-L-talose. 

Iseki, K. Catalytic asymmetric synthesis of fluoro-organic compounds Mukaiyama-aldol and Henry reactions. ACS Symp. Ser. 2000, 746, 38-51. 

The aldol reaction and related processes have been of considerable importance in organic synthesis. The control of syn/anti diastereoselectivity, enantioselectivity and chemoselectivity has now reached impressive levels. The use of catalysts is a relatively recent addition to the story of the aldol reaction. One of the most common approaches to the development of a catalytic asymmetric aldol reaction is based on the use of enantiomerically pure Lewis acids in the reaction of silyl enol ethers with aldehydes and ketones (the Mukaiyama reaction) and variants of this process have been developed for the synthesis of both syn and anti aldol adducts. A typical catalytic cycle is represented in Figure 7.1, where aldehyde (7.01) coordinates to the catalytic Lewis acid, which encourages addition of the silyl enol ether (7.02). Release of the Lewis acid affords the aldol product, often as the silyl ether (7.03). 

Shiina I, Saitoh K, Frechard-Ortuno I, Mukaiyama T (1998) Total Asymmetric Synthesis of Taxol by Dehydration Condensation between 7-TES Baccatin III and Protected N-Benzoylphenylisoserines Prepared by Enantioselective Aldol Reaction. Chem Lett 3... 

The Mukaiyama aldol reaction has also been used in the enantioselective asymmetric synthesis of 5-hydroxy-P-keto ester derivatives. Katsuki and coworkers utilized the chiral Cr(salen) complex 69 for the catalysis of the aldol reaction in the presence of water or alcohol. The presence of alcohol in the reaction greatly increases the enantioselectivity of the aldol addition. In the reaction of the silyl enol ether 92 with the aldehyde 93 in the presence of the catalyst 69, triethylamine, and isopropanol yielded the aldol adduct 94 in high yield (87%) and excellent enantioselectivity (97% ee). 

Moreau, X., Bazan-Tejeda, B., and Campagne, J.-M. (2005) Catalytic and asymmetric vinylogous Mukaiyama reactions on aliphatic ketones Eormal asymmetric synthesis of taurospongin A. J. Am. Chem. Soc., 127, 7288-7289. 

Catalytic Asymmetric Synthesis of Fluoroorganic Compounds Mukaiyama-Aldol and Henry Reactions... 

The Mukaiyama-aldol reaction of silyl enol ethers is one of the most important carbon-carbon bond-forming reactions in organic synthesis. Therefore, its application to catalytic asymmetric synthesis has been investigated in depth for the last decade (52-56). In an analogy to the F-C reaction of vinyl ether, if a catalytic asymmetric F-C reaction proceeds under Mukaiyama conditions to give additional reactive silyl enol hers, sequential reactions with electrophiles could provide further functionalized products (chiral syn or a fi-a,/8-dihydroxythioesters as a-... 

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