Synthesis and molecular structures of novel .alpha.-amino organoaluminum ester enolates. Key intermediates in the selective formation of trans-3-amino-2-azetidinones
作者:Fred H. Van der Steen、Guido P. M. Van Mier、Anthony L. Spek、Jan Kroon、Gerard Van Koten
DOI:10.1021/ja00015a031
日期:1991.7
Full-matrix least-squares refinement on F converged at R = 0.05 1 and R, = 0.043. The structures of enolates 3 and 3’ in solution as well as the reactions of these enolates with imines 4 is discussed. It is shown that both dimeric enolates 3 as well as monomeric adducts 3’ may act as the reactive intermediates in the one-pot synthesis of 3-amino-2-azetidinones 5 and 6, which is characterized by the reactions
Chromium-53 nuclear magnetic resonance studies of pentacarbonylchromium carbene complexes
作者:Andreas. Hafner、Louis S. Hegedus、Guy. DeWeck、Bruce. Hawkins、Karl H. Doetz
DOI:10.1021/ja00233a018
日期:1988.12
The sup 53}Cr NMR spectra of 46 chromium-carbene complexes were recorded, and chemicalshift and line width data are reported, along with associated infrared, uv-visible, and sup13}CNMR spectroscopic data. The sup 53}Cr chemicalshifts correlated very well with the donor-acceptor properties of the carbene ligand and were quite sensitive to steric influences on efficiency of pi}-overlap of the