Controlling Keto–Enol Tautomerism of Ureidopyrimidinone to Generate a Single-Quadruple AADD-DDAA Dimeric Array

• Published in: Organic letters Vol. 22; no. 18; pp. 7305 - 7309
• Main Authors: Zhang, Jing, Qi, Shuaiwei, Zhang, Chenyang, Fan, Zengming, Ding, Qinwen, Mao, Shizhong, Dong, Zeyuan
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 18.09.2020; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Organic; Physical Sciences; Science & Technology; DYNAMICS; HYDROGEN; TRANSPORT; PROTON-TRANSFER
• ISSN: 1523-7060; 1523-7052
• DOI: 10.1021/acs.orglett.0c02644

Units of ureidopyrimidinone (UPy) which dimerize via strong quadruple hydrogen bonding are widely used for the construction of supramolecular systems. This self-complementary system exists in the tautomerism equilibrium of 4­[1H]-pyrimidinone dimer and pyrimidin-4-ol dimer, making generated supramolecular assembly systems essentially complicated. In this contribution, a rational but simple design concept is described for preorganizing the self-complementary quadruple hydrogen bonding of UPy via supramolecular strategy into a single-quadruple DDAA-AADD dimeric array. With this concept, the designed UPy derivatives form only 4­[1H]-pyrimidinone dimer with a ketone configuration via intermolecular hydrogen-bonding interactions, both in the solid state as well as in solution, as is evident from single-crystal X-ray diffraction and 1H NMR spectroscopy. The single DDAA-AADD dimeric array provides defined noncovalent driving forces that can be used to generate constitutionally clear supramolecular structures that are vitally important in the fields of supramolecular chemistry and materials.