TY - JOUR ID - pittir19544 UR - http://d-scholarship-dev.library.pitt.edu/19544/ IS - 25 A1 - Dandapani, S A1 - Curran, DP Y1 - 2004/12/10/ N2 - First generation fluorous DEAD reagent bis(perfluorohexylethyl)azo dicarboxylate (C6F13(CH2)2O 2-CN=NCO2(CH2)2C6F13, F-DEAD-1) has been shown to underperform relative to diisopropylazodicarboxylate in difficult Mitsunobu reactions involving hindered alcohols or less acidic pronucleophiles (phenols). Two new second generation fluorous reagents bearing propylene spacers instead of the ethylene spacers show expanded reaction scope while retaining the easy fluorous separation features. Byproducts from "half fluorous" reagent perfluorooctylpropyl tert-butyl azo dicarboxylate (C8F17(CH2)3O 2CN=NCO2tBu, F-DEAD-2) can be removed by fluorous flash chromatography, and byproducts from bis(perfluorohexylpropyl)azo dicarboxylate (C6F13(CH2)3O 2CN=NCO2(CH2)3C6F 13, F-DEAD-3) can be removed by fluorous solid-phase extraction. The new reagents promise to provide general and complementary solutions for separation problems in Mitsunobu reactions without restricting reaction scope. JF - Journal of Organic Chemistry VL - 69 SN - 0022-3263 TI - Second generation fluorous DEAD reagents have expanded scope in the Mitsunobu reaction and retain convenient separation features SP - 8751 AV - public EP - 8757 ER -