Formation of C-0 bonds

In addition to its utility in the enantioselective formation of C-0 bonds (cf. Scheme 15), Trost s chiral ligand 102 has been used in the catalytic asymmetric synthesis of C-N bonds. An impressive application of this protocol is in the enantioselective total synthesis of pancrastatin by Trost (Scheme 17) H9i Thus, Pd-catalyzed desymmetrization of 112 leads to the formation of 113 efficiently and in > 95 % ee. The follow-up use of the N3 group to fabricate the requisite cyclic amide via isocyanate 117 demonstrates the impressive versatility of this asymmetric technology. 

M. Zaidlewicz, Formation of C-0 Bonds by Hydroboration of Olefinic Double Bonds Followed by Oxidation, in Stereoselective Synthesis (Houben-Weyl) 4th ed. 1996, (G. Helmchen, R. W. Hoffmann, J. Mulzer, E. Schaumann, Eds.), 1996, Vol. E 21 (Workbench Edition), 8, 4519 1530, Georg Thieme Verlag, Stuttgart. 

J. O. Metzger, Reactions of Radicals with Formation of C,0-Bond, in Methoden Org. Chem. (Houben-Weyl) 4th ed. 1952-, C-Radicals (M. Regitz, B. Giese, Eds.), Vol. E19a, 383, Georg Thieme Verlag, Stuttgart, 1989. 

---