... Please enable JavaScript to use all the features on this page. Tetrahedron Letters. Volume 53, Issue 32, 8 August 2012, Pages 4074–4076. Cover image Cover image. N-Acyl 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) tetraphenylborate salts as O-acylating agents. ...