Contemporary organic chemists employ a broad range of catalytic and stoichiometric methods to construct molecules for applications in many fields, including material sciences1, pharmaceuticals2–5, agrochemicals, and sensors6. The potential utility of a synthetic method can be greatly reduced if it relies on the use of air- and/or moisture-sensitive reagents or catalysts. Furthermore, many synthetic chemistry laboratories have numerous containers of partially used reagents that have been spoiled by exposure to the ambient atmosphere. This is exceptionally wasteful from both an environmental and a cost perspective. In this manuscript, we report an encapsulation method through which air- and moisture-sensitive sensitive compounds can be rendered stable and stored on a laboratory bench top. We demonstrate this approach in three contexts, by describing single use capsules that contain all of the reagents (i.e., catalysts, ligands, and bases) necessary for palladium-catalyzed carbon–fluorine7–9, carbon–nitrogen10,11, and carbon–carbon12 bond forming reactions. The strategy described in this paper should be broadly applicable to a wide range of reagents and catalysts and should have the power to be transformative in preparative organic chemistry, particularly for inexperienced chemists. In addition, this approach will reduce the amount of tedious and time-consuming weighing procedures for the synthetic chemist performing these techniques on a large number of substrate combinations.

The experiments described here clarify the mechanism and origin of the enantioselectivity of the oxidation of racemic secondary alcohols catalyzed by chiral Mn(III)-salen complexes using HOBr, Br 2 /H 2 O/KOAc or PhI(OAc) 2 /H 2 O/KBr as a stoichiometric oxidant. Key points of the proposed pathway include (1) the formation of a Mn(V)-salen dibromide, (2) its subsequent reaction with the alcohol to give an alkoxy-Mn(V) species, and (3) carbonyl-forming elimination to produce the ketone via a highly organized transition state with intramolecular transfer of hydrogen from carbon to an oxygen of the salen ligand.

In search of alternatives to unstable or unreliable 2-pyridylboron reagents, we have explored two new varieties of solid, moderately air-stable 2-pyridylzinc reagents. Both reagents can be manipulated in air and are competent nucleophiles in Negishi cross-coupling reactions.

A method for the preparation of aryl and heteroaryl sulfonamides using 2,4,6-trichlorophenyl chlorosulfate (TCPC) is described. The reaction of 2-pyridylzinc reagents with TCPC resulted in 2,4,6-trichlorophenyl (TCP) pyridine-2-sulfonates, and the parent pyridine-2-sulfonate was shown to react with amines. Less electron-rich aryl- and heteroarylzinc reagents reacted with TCPC to afford sulfonyl chlorides that were converted in situ to sulfonamides.

Aryl‐ and heteroarylzinc reagents react with 2,4,6‐trichlorophenyl chlorosulfate (TCPC) to afford sulfonyl chlorides which are in situ converted to the corresponding sulfonamides by rapid reaction with various amines.

Two new varieties of solid, moderately air‐stable 2‐pyridylzinc reagents are explored as alternatives to unstable or unreliable 2‐pyridylboron reagents.