Bioinspired organocatalysis of C-C bond-forming reactions

Over the last few decades, there has been a particular attention to the development of new and efficient synthetic strategies inspired to mimic the performance, selectivity and specificity in biological processes. In this context, the replacement of organic solvents with more environmentally benign water and the design of "artificial" enzymes with the desirable features of natural ones but without their intrinsic drawbacks such as poor substrate versatility and ease of denaturation, represent promising fields. We report here our recent studies on these two issues based on the use of calixarene derivatives. In fact, their hydrophobic character combined with their recognition abilities make them valid organocatalysts for the vinylogous Mukaiyama aldol reaction under "on-water" conditions and provide a confined reaction environment to efficiently conduct 1,3-dipolar cycloaddition of nitrones to alfa,beta-unsaturated aldehydes