A New and Efficient Preparation of Cyclic Carbodiimides from Bis(iminophosphoranes) and the System Boc2O/DMAP
摘要:
A one-pot synthesis of cyclic carbodiimides which involves reaction of C,C-bis(aryliminophosphoranes) connected by aliphatic bridges with Boc(2)O in the presence of DMAP is described. The method is also applicable when a heteroatom such as oxygen or nitrogen is incorporated into the tether connecting the two aromatic rings. A conformation study has been carried out on carbodiimide 23a, which posseses a central nine-membered ring, using H-1 NMR spectroscopy and semiempirical as well as molecular mechanics calculations.
A New and Efficient Preparation of Cyclic Carbodiimides from Bis(iminophosphoranes) and the System Boc2O/DMAP
摘要:
A one-pot synthesis of cyclic carbodiimides which involves reaction of C,C-bis(aryliminophosphoranes) connected by aliphatic bridges with Boc(2)O in the presence of DMAP is described. The method is also applicable when a heteroatom such as oxygen or nitrogen is incorporated into the tether connecting the two aromatic rings. A conformation study has been carried out on carbodiimide 23a, which posseses a central nine-membered ring, using H-1 NMR spectroscopy and semiempirical as well as molecular mechanics calculations.
POLY(ORGANOPHOSPHAZENE) COMPOSITION FOR BIOMATERIALS
申请人:SONG Soo-Chang
公开号:US20130004455A1
公开(公告)日:2013-01-03
Provided are a use of chemically-crosslinkable, poly(organophosphazene)s for biomaterials, chemically-crosslinkable poly(organophosphazene)s with a physiologically active substance covalently-bonded thereto, a use thereof for biomaterials, and a process for preparing the same. The chemical crosslinkings can be made by UV irradiation, and/or a crosslinker, and/or an additive, and/or an enzyme, and/or a mixing of at least one polymer.
The Staudinger reaction between bis(azides) and bis(phosphines) under mild conditions provides macrocyclic bis(iminophosphoranes) (at least 12-membered rings) in excellent to moderate yield. The method also allows the incorporation of a heteroatom into the chain connecting the two aromatic or heteroaromatic rings.