The manufacturing of a three‐dimensional product from a computer‐driven digital model (3D printing) has found extensive applications in several fields. Additive manufacturing technologies offer the possibility to fabricate ad hoc tailored products on demand, at affordable prices, and have been employed to make customized and complex items for actual sale. However, despite the great progress and the countless opportunities offered by the 3D printing technology, surprisingly a relatively limited number of applications have been documented in organic chemistry. This Minireview will focus specifically on the exploitation of additive manufacturing technologies in the synthesis of organic compounds, and, in particular, on the use of 3D‐printed catalysts and 3D printed reactors, and on the fabrication and use of 3D printed flow reactors.

A simple procedure to convert protein data bank files (.pdb) into a stereolithography file (.stl) using VMD software (Virtual Molecular Dynamic) is reported. This tutorial allows generating, with a very simple protocol, threedimensional customized structures that can be printed by a low-cost 3D-printer, and used for teaching chemical education topics. With the use of the free licensed and multiplatform software, colored input geometries can be obtained by a simple-click modification procedure in order to generate .obj and .mtl files. An easy protocol to create personal .pdb files for 3D-printing technology is also reported.

A catalytic, enantioselective, Lewis base-catalyzed α-sulfenylation of silyl enol ethers has been developed. To avoid acidic hydrolysis of the silyl enol ether substrates, a sulfenylating agent that did not require additional Brønsted acid activation, namely N-phenylthiosaccharin, was developed. Three classes of Lewis bases—tertiary amines, sulfides, and selenophosphoramides—were identified as active catalysts for the α-sulfenylation reaction. Among a wide variety of chiral Lewis bases in all three classes, only chiral selenophosphoramides afforded α-phenylthio ketones in generally high yield and with good enantioselectivity. The selectivity of the reaction does not depend on the size of the silyl group but is highly sensitive to the double bond geometry and the bulk of the substituents on the double bond. The most selective substrates are those containing a geminal bulky substituent on the enoxysilane. Computational analysis revealed that the enantioselectivity arises from an intriguing interplay among sterically guided approach, distortion energy, and orbital interactions.

3D-printed flow reactors were designed, fabricated from different materials (PLA, HIPS, nylon), and used for a catalytic stereoselective Henry reaction. The use of readily prepared and tunable 3D-printed reactors enabled the rapid screening of devices with different sizes, shapes, and channel dimensions, aimed at the identification of the best-performing reactor setup. The optimized process afforded the products in high yields, moderate diastereoselectivity, and up to 90 % ee. The method was applied to the continuous-flow synthesis of biologically active chiral 1,2-amino alcohols (norephedrine, metaraminol, and methoxamine) through a two-step sequence combining the nitroaldol reaction with a hydrogenation. To highlight potential industrial applications of this method, a multistep continuous synthesis of norephedrine has been realized. The product was isolated without any intermediate purifications or solvent switches.

The design and synthesis of new chiral Lewis bases is a field of extraordinary activity; in this context, while N-oxides derived from both N-heterocyclic systems and aliphatic amines have found widespread applications in organocatalysis, quite surprisingly phosphine oxides have been used less frequently. This contribution will highlight the relatively few examples of stereoselective transformations organocatalyzed by chiral phosphine oxides, discussing the different proposed reaction mechanisms and identifying topics for future investigation in what can be most certainly defined as an "Emerging Area".