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Upstream product

• 638-21-1 phenylphosphane 
• 573710-26-6 6^A,6^B,6^D,6^E-tetra-O-methylsulfonyl-2^A,2^B,2^C,2^D,2^E,2^F,3^A,3^B,3^C,3^D,3^E,3^F,6^C,6^F-tetradeca-O-methyl-α-CD 

Relevant academic research and scientific papers

Diastereospecific synthesis of phosphinidene-capped cyclodextrins leading to "introverted" ligands

α-Cyclodextrins (α-CDs) containing "PPh" units which cap the primary face of the CD were obtained in high yield by reaction of Li2PPh with A,B- or A,C-dimesylated and A,B,D,E-tetramesylated precursors; the resulting phosphines are diaster-eomer

Synthesis and properties of TRANSDIP, a rigid chelator built upon a cyclodextrin cavity: Is TRANSDIP an authentic trans-spanning ligand?

The C2-symmetrical diphos-phane TRANSDIP was obtained in high yield by treating 6A,6B,6D.6E -tetramesylated, permethylated α-cyclodex-trin with PPhLi2 in excess. The double cascade cyclisation thus produced is regioselective as phosphinidene capping involves only adjacent glucose units. It is also stereospecific, as both lone pairs on the phosphorus atoms are orientated towards the cyclodextrin axis. The restricted flexibility of the phosphorus atoms, which are part of nine-membered heterocyclic rings, is responsible for JPC spin-spin couplings with the eight-bond distant CH2OMe carbon atoms of glucose units C and F. The treatment of TRANSDIP with Group 10 metal dihalides quantitatively gave square-planar chelate complexes, in which a M-X bond points towards the centre of the cavitand. The favourable P...P separation and the directional control of the lone pairs on the phosphorus atoms rule out the possibility of forming binuclear complexes or higher oligomers. Further, in all the complexes, the phosphorus atoms are in a trans arrangement. TRANSDIP may therefore be regarded as an authentic trans-spanning diphosphane. In the complex [NiBr2·TRANSDIP], the cavity provides effective protection of the encapsulated M-X bond towards nucleophilic attack by MeLi. The same complex, upon activation with methyl-aluminoxane, efficiently dimerises ethene and propene.