Effective, selective hydroalkoxylation/cyclization of alkynyl and allenyl alcohols mediated by lanthanide catalysts

INOR 537

SungYong Seo, s-seo@northwestern.edu1, Xianghua Yu, xyu@northwestern.edu1, and Tobin J. Marks, t-marks@northwestern.edu2. (1) Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, (2) Department of Chemistry and the Materials Research Center, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208
Catalytic hydroalkoxylation/cyclization reactions of alkynyl and allenyl alcohols are efficiently mediated by homoleptic lanthanide amides Ln[N(SiMe3)2]3 (Ln = La, Nd, Sm, Y, and Lu). Conversions are found to be highly selective with products distinctly different from those produced by conventional transition metal catalysts. Turnover frequencies as high as 18.0 h-1 at 60 °C are observed. Kinetic studies indicate that these transformations are zero-order in [substrate] and first-order in [catalyst]. Catalytic cycles are proposed in which insertion of C–C unsaturation into a Ln–O bond is turnover-limiting.
 

Chemistry of Lanthanides and Actinides
2:00 PM-5:20 PM, Tuesday, August 21, 2007 BCEC -- 212, Oral

Division of Inorganic Chemistry

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007