Asymmetric Catalytic Hydrogenation Reactions

Crego-Calama M, Reinhoudt DN, ten Cate MGJ (2005) Templation in Noncovalent Synthesis of Hydrogen-Bonded Rosettes. 249 in press Crepy KVL, Imamoto T (2003) New P-Chirogenic Phosphine Ligands and Their Use in Catalytic Asymmetric Reactions. 229 1-40 Cristau H-J, see Taillefer M (2003) 229 41-73... 

A similar strategy served to carry out the last step of an asymmetric synthesis of the alkaloid (—)-cryptopleurine 12. Compound 331, prepared from the known chiral starting material (l )-( )-4-(tributylstannyl)but-3-en-2-ol, underwent cross-metathesis to 332 in the presence of Grubbs second-generation catalyst. Catalytic hydrogenation of the double bond in 332 with simultaneous N-deprotection, followed by acetate saponification and cyclization under Mitsunobu conditions, gave the piperidine derivative 333, which was transformed into (—)-cryptopleurine by reaction with formaldehyde in the presence of acid (Scheme 73) <2004JOC3144>. 

An analysis of the processes listed in Table 37.2 shows that asymmetric hydrogenation of C=C and C=0 functions is by far the predominant transition metal-catalyzed transformation applied for industrial processes, followed by epoxida-tion and dihydroxylation reactions. On the one hand, this is due to the broad scope of catalytic hydrogenation, and on the other hand it could be attributed to... 

Asymmetric Catalytic Hydrogenation and Other Reduction Reactions... 

ASYMMETRIC CATALYTIC HYDROGENATION AND OTHER REDUCTION REACTIONS... 

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