“…Rosin-derived bifunctional thiourea organocatalysts, originated from the abundantly available natural rosin, were revealed to be highly efficient for some catalytic asymmetric reactions, including Aza-Henry [28], Mannich reaction [29,30], Aldol reaction [31,32], Michael addition [33][34][35][36], and Friedel-Crafts alkylation [37]. The thiourea moiety of those organocatalysts is usually introduced at position C-4 of rosin skeleton, while the tertiary amine moiety is either 1,2-diaminocyclohexane 1 or cinchona alkaloid 2 (Figure 1).…”