Improved Synthesis of Asymmetrical Substituted 1H-1,2,4-Diazaphospholes

GRAPHICAL ABSTRACT

Abstract

The reaction of tris(trimethylsilyl)phosphine and a mixture of two different N,N-dimethylalkylamides (1a,b), followed by the treatment with dry hydrazine in situ, resulted in seven asymmetrical 3,5-disubstituted 1H-1,2,4-diazaphospholes (3a-g). Compounds 3a-g are characterized by single crystal X-ray structural analysis. The present protocol provides a general route to this class of molecules without using phosphaalkynes or phosphaalkenes.

Keywords:

• Asymmetrical 1H-1,2,4-diazaphosphole
• hydrogen bonding
• X-ray structure
• synthesis

ACKNOWLEDGMENT

Liu thanks Dr. Hongbo Tong (Shanxi University) for the help with X-ray diffraction analysis.

FUNDING

We gratefully acknowledge financial support from the Program for the Top Young and Middle-Aged Innovative Talents of Higher Learning Institutions of Shanxi (TYMIT 2011), the Doctoral Foundation of Chinese Education Ministry (grant no. 20111404110001), National Natural Science Foundation of China (NSFC; grant no. 21272143), the Program for Changjiang Scholar and Innovative Research Team in University (IRT1156), State R&D Program of China (no. 2012BAE06B08), the State Key Laboratory of Advanced Technology for Comprehensive Utilization of Platinum Metals, Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi (STIP 20120016), Natural Science Foundation of Shanxi (grant no. 2013011011-2), and Natural Science Foundation of Shanxi Normal University (grant no. 872018).

SUPPLEMENTAL MATERIAL

Supplementary data for this article can be accessed on the publisher's website, www.tandfonline.com/gpss.

The X-ray crystallographic data, spectroscopic data, and the crystallographic plots of 3 are deposited in the Supporting Information.