... presence of oxygen by use of Pd(OAc) 2 immobilized on oligo-p-phenyleneterephthalamide in ... dehydrogenation upon treatment with t-BuOK in DMF under air (eq 1). 7 figure ... eq 5). 13 Analogously, α-iodomethylene triphenylphosphoranes were used for the synthesis of propiolic ...