Project Report

Azaindoles, such as 5-azaindoles, are a class of heterocycles commonly used in the synthesis of biologically active compounds and natural products. The disadvantage of previous approaches is that in order to synthesize 5-azaindoles with additional substituents, highly functionalized starting materials must first be synthesized or further transformations must be done after the azaindoles are formed. Recently, Professor Zhenfeng Xi at Peking University has reported the zirconocene-mediated coupling reaction of a silyl-tethered diyne with three molecules of organonitrile to form highly substituted 5-azaindoles upon hydrolysis in one-pot. The advantage of Xi’s method is that a large number of organonitriles are commercially available and silyl-tethered diynes are easily synthesized from terminal alkynes, which makes this method amenable to the synthesis of a wide variety of 5-azaindoles. My work on this project included trying to expand the substrate scope of azaindoles that could be synthesized by modifying the alkyne substituents on the silyl-tethered diynes. In particular, modifying the diyne to contain a silyl group was especially desirable as the resulting azaindole product would contain an additional functional group handle that could be exploited for additional chemical transformations. Additional work involved attempting to capture reaction intermediates with electrophiles other than organonitriles. Xi and coworkers have previously completed detailed mechanistic studies wherein they were able to isolate and characterize some of the reaction intermediates present in their zirconium-mediated method. By intercepting these intermediates with different electrophiles, such as carbodiimides or organoazides, our hope was to generate novel heterocycles that could be used in the synthesis of biologically active compounds.

Agency
National Science Foundation (NSF)
Institute
Office of International and Integrative Activities (IIA)
Application #
1107755
Program Officer
Carter Kimsey
Project Start
Project End
Budget Start
2011-06-01
Budget End
2012-05-31
Support Year
Fiscal Year
2011
Total Cost
$5,700
Indirect Cost
Name
Cheng Kevin
Department
Type
DUNS #
City
Philadelphia
State
PA
Country
United States
Zip Code
19104