Impact on mechanism of reaction with the presence of a bulky group on the α-carbon of chloroformate esters

CHED 731

Shannon E. Carter, shannc022@yahoo.com1, Malcolm J. D'Souza, dsouzama@wesley.edu1, and Dennis N. Kevill, dkevill@niu.edu2. (1) Department of Chemistry, Wesley College, 120 N. State Street, Dover, DE 19901, (2) Department of Chemistry & Biochemistry, Northern Illinois University, DeKalb, IL 60115
Bulky alkyl chloroformate esters are efficient precursors in the synthesis of a wide variety of commercial products. For example, neopentyl chloroformate is used to develop an extremely inert photoresist resin poly 4-neopentyloxycarbonyloxy styrene. Recent mechanistic work using substituent effects, solvent effects, and product studies, has suggested that a number of these compounds solvolyze by competing reaction channels, involving association-dissociation and ionization. Here we study the influence of solvent variation in the study of neopentyl chloroformate in aqueous binary mixtures of ethanol, methanol, acetone, 2,2,2-trifluoroethanol (TFE), 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP), and TFE-ethanol mixtures. Initial data obtained suggests significant differences in the mechanisms of reaction of neopentyl chloroformate (with a sp2 carbon) when compared to that proposed for neopentyl chloride (with a sp3 carbon). In the solvents studied, we see no hydride or methyl shifts (indicated by robustness of data) for neopentyl chloroformate.

[Support by NIH NCRR INBRE grant number; 2 P20 RR016472-07]

 

Undergraduate Research Poster Session: Polymer Chemistry
11:00 AM-1:00 PM, Monday, April 7, 2008 Morial Convention Center -- Hall A, Poster

Division of Chemical Education

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008