An efficient transformation of cyclic ene-carbamates into omega-(N-formylamino)carboxylic acids by ruthenium tetroxide oxidation

The ruthenium tetroxide (RuO(4)) oxidation of cyclic ene-carbamates resulted in the endo-cyclic carbon-carbon double bond cleavage to afford the corresponding omega-(N-formylamino)carboxylic acids in good yields. Substituted cyclic ene-carbamates derived from (3R)-3-hydroxypiperidine hydrochloride were converted into the N-Boc 4-aminobutyric acids by utilization of the RuO(4) oxidation as the key step, which were further transformed into (3R)-4-amino-3-hydroxybutyric acid, an important key intermediate for the synthesis of L-carnitine.     

Isolation and characterization of some very stable 1-phospha-allenes: sterically protected iminomethylene- and ethenylidenephosphines

Very stable iminomethylenephosphine (3) and ethenylidenephosphine (4) were obtained by steric protection with the 2,4,6-tri-tertbutylphenyl group and some of the spectroscopic data are described.     

Sterically Protected Unusual Phosphorus Compounds in Lower Coordination States: Diphosphenes,Phosphaethylenes, and 1-Phospha- and 1,3-Diphosphaallenes

Abstract

Physicochemical properties and chemical reactivities of some sterically protected unusual phosphorus compounds in lower coordination states are discussed such as diphosphenes, phosphaethylenes, and 1-phospha- and 1,3-diphosphaallenes.     

Synthesis and structure of 1‐phospholyl‐ and di(1‐phospholyl)acetylenes and the corresponding sulfides

The acetylenes possessing one and two 1‐phospholyl groups were synthesized by reaction of the alkynyl Grignard reagents with the 1‐chlorophosphole and converted to the corresponding phosphole sulfides. Reaction of the 1‐phenylethynylphosphole sulfide with CpCo(CO)₂ resulted in η⁴‐complexation on the phosphole moiety. The structures of the di(1‐phospholyl)acetylene disulfide and the [η⁴‐(1‐phenylethynylphosphole sulfide)]cobalt(I) complex were characterized by X‐ray crystallography. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:344–349, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20230     

Sterically and Electronically Stabilized Organophosphorus Compounds

Abstract

The diatkylamino groups and the methoxy group were employed in a protective group and attempts were made to prepare dithioxo- and selenoxo-phosphoranes.