Betzl, Wolfgang; Hettstedt, Christina; Karaghiosoff, Konstantin
(8. November 2012):
New anellated 4H-1,4,2-diazaphospholes.
In: New Journal of Chemistry, Vol. 37, No. 2: pp. 481-487
Five new anellated 4H-1,4,2-diazaphospholes including the first examples of chiral 4H-1,4,2-diazaphospholes with the (-)-menthyl substituent have been prepared by two main routes: Hantzsch type cyclocondensation of 4-phenyl-2-amino-1,3-thiazole with chloromethyl dichlorophosphine and 4+1 cyclocondensation of cycloimmonium salts derived from 4-phenyl-2-amino-1,3-thiazole and 2-aminopyridine with PCl3 and NEt3. The new compounds have been characterized by multinuclear (H-1, C-13, P-31) NMR spectroscopy. Controlled hydrolysis of 5-phenylthiazolo3,2-d]1,4,2]diazaphosphole 2a with two equivalents of water yields the corresponding zwitterionic phosphinate 9, the structure of which was elucidated by single crystal X-ray diffraction. The structure in the solid state is governed by strong N-H center dot center dot center dot O hydrogen bonding resulting in chains along the crystallographic a-axis. The chloroform molecules are integrated in the chains by weaker C-H center dot center dot center dot O bonds and C-Cl center dot center dot center dot C halogen bonds.