Helvetica chimica acta

Transesterifications with 1, 8??Diazabicyclo [5.4. 0] undec??7??ene/Lithium Bromide (DBU/LiBr)–Also Applicable to Cleavage of Peptides from Resins in Merrifleld …

D Scebach, A Thaler, D Blaser, SY Ko

Index: Seebach, Dieter; Thaler, Adrian; Blaser, Denis; Ko, Soo Y. Helvetica Chimica Acta, 1991 , vol. 74, # 5 p. 1102 - 1118

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Citation Number: 93

Abstract

Abstract A mixture of the amidine base 1, 8-diazabicyclo [5.4. 0] undec-7-ene (DBU) and LiBr (preferably 0, 5 and 5 equiv., resp.) turns out to be a highly efficient catalyst (at 0–25) for saponifications (in THF/H 2 O) and transesterifications (in ROH). The scope and limitations of the method are determined using ca. two dozens of different ester/alcohol combinations (Schemes 2 and 3). The investigation is focused on peptides as substrates. Under ...