Ir-Catalyzed Enantioselective, Intramolecular Silylation of Methyl C–H Bonds

Enantioselective Intramolecular CH - Insertions upon Cu - Catalyzed Decomposition of Phenyliodonium Ylides . †

The Cu-catalyzed intramolecular CH insertion of phenyliodonium ylide 5b has been investigated at 0° C in the presence of several chiral ligands. Enantioselectivities vary in the range of 38–72 %, and are higher than those resulting from reaction of the diazo compound 5c at 65° C. The results are consistent with a carbenoid mechanism for Cu-catalyzed decomposition of phenyliodonium ylides.

Highly diastereo- and enantioselective intramolecular amidation of saturated C-H bonds catalyzed by ruthenium porphyrins.

NMR and IR Investigations of Strong Intramolecular Hydrogen Bonds.

For the purpose of this review, strong hydrogen bonds have been defined on the basis of experimental data, such as OH stretching wavenumbers, νOH, and OH chemical shifts, δOH (in the latter case, after correction for ring current effects). Limits for O-H···Y systems are taken as 2800 > νOH > 1800 cm-1, and 19 ppm > δOH > 15 ppm. Recent results as well as an account of theoretical advances are p...

Gold(I)-Catalyzed Enantioselective Intramolecular Hydroamination of Allenes with Ureas.

Enantioselective intramolecular hydroamination of N-allenyl ureas catalyzed by an enantiomerically enriched bis(gold) phosphine complex forms pyrrolidine derivatives in good yield with up to 93% ee.

Lewis Base Catalyzed, Enantioselective, Intramolecular Sulfenoamination of Olefins

A method for the enantioselective, intramolecular sulfenoamination of various olefins has been developed using a chiral BINAM-based selenophosphoramide, Lewis base catalyst. Terminal and trans disubstituted alkenes afforded pyrrolidines, piperidines, and azepanes in high yields and high enantiomeric ratios via enantioselective formation and subsequent stereospecific capture of the thiiranium in...