Single atom catalysts enable quasi-homogeneous synthesis of quinazoline

The 2-substituted quinazoline moiety is the core structure of many fine chemicals, pharmaceutical agents and functional molecules. The effective synthetic strategies for the 2-substituted quinazolines are highly significant. Herein, we presented a new strategy to prepare various SACs (Mn-SA@YBC, Ni-SA@YBC, Cu-SA@YBC and Co-SA@YBC) supported on yeast-derived biochar materials for the first time. These SACs remained the original morphology of yeasts. The studies of catalytic performance of SACs revealed that Mn-SA@YBC exhibited excellent catalytic performance than the Mn-nano@YBC in the dehydrogenation of 2-aminobenzyl alcohol and aromatic nitriles forming 2-substituted quinazolines. The Mn-SA@YBC exhibited good stability, and still showed high catalytic activity without any significant loss after recycled six times. The atomically dispersed Mn atoms were observed in the aberration-corrected high-angle annular-dark-field scanning transmission electron microscopy (HAADF-STEM) images of the freshly prepared and recycled Mn-SA@YBC which proved the good stability and reusability of the Mn-SA@YBC. XANES and XPS analysis indicated that the Mn atom of Mn-SA@YBC had the Mn-N3P coordination structure which was different from previous reports. A reasonable reaction mechanism had been proposed. It was believed that this work paved a new way for the design and preparation of active single atomic site catalysts on biochar materials.