TY - JOUR A1 - Urriolabeitia, Esteban P. A1 - Sánchez, Pablo A1 - Pop, Alexandra A1 - Silvestru, Cristian A1 - Laga, Eduardo A1 - Jiménez, Ana I. A1 - Cativiela, Carlos T1 - Synthesis of esters of diaminotruxillic bis-amino acids by Pd-mediated photocycloaddition of analogs of the Kaede protein chromophore JF - Beilstein Journal of Organic Chemistry PY - 2020/// VL - 16 SP - 1111 EP - 1123 SN - 1860-5397 DO - 10.3762/bjoc.16.98 PB - Beilstein-Institut JA - Beilstein J. Org. Chem. UR - https://doi.org/10.3762/bjoc.16.98 KW - amino acids KW - C–H activation KW - Kaede protein KW - oxazolones KW - photocycloaddition N2 - The stereoselective synthesis of truxillic bis-amino esters from polyfunctional oxazolones is reported. The reaction of 4-((Z)-arylidene)-2-(E)-styryl-5(4H)-oxazolones 2 with Pd(OAc)2 resulted in ortho-palladation and the formation of a dinuclear open-book complexes 3 with carboxylate bridges, where the Pd atom is C^N bonded to the oxazolone. In 3 the two exocyclic C=C bonds of the oxazolone are in a face-to-face arrangement, which is optimal for their [2 + 2] photocycloaddition. Irradiation of dimers 3 in CH2Cl2 solution with blue light (465 nm) promoted the chemo- and stereoselective [2 + 2] photocycloaddition of the exocyclic C=C bonds and the formation of cyclobutane-containing ortho-palladated complexes 4. Treatment of 4 with CO in a MeOH/NCMe mixture promoted the methoxycarbonylation of the palladated carbon and the release of the corresponding ortho-functionalized 1,3-diaminotruxillic bis-amino esters 5 as single isomers. ER -