The development of 2-isocyanopyridines as novel convertible isocyanides for multicomponent chemistry is reported. Comparison of 12 representatives of this class revealed 2-bromo-6-isocyanopyridine as the optimal reagent in terms of stability and synthetic efficiency. It combines sufficient nucleophilicity with good leaving group capacity of the resulting amide moiety under both basic and acidic conditions. To demonstrate the practical utility of this reagent, an efficient two-step synthesis of the potent opioid carfentanil is presented.

We report a highly diastereoselective interrupted Ugi reaction to construct a broad range of structurally congested and stereochemically complex spiroindolines from tryptamine-derived isocyanides. The reaction is facilitated by using fluorinated alcohols (TFE or HFIP) as solvents and tolerates a broad range of amines, aldehydes and 2-isocyanoethylindoles to give polycyclic products in moderate to excellent yields.

Herein, we describe the versatile application of triphenylmethyl (trityl) isocyanide in multicomponent chemistry. This reagent can be employed as a cyanide source in the Strecker reaction and as convertible isocyanide in the preparation of N-acyl amino acids by Ugi 4CR/detritylation and free imidazo[1,2-a]pyridin-3-amines by a Groebke-Blackburn-Bienaymé 3CR condensation/deprotection protocol. The mechanisms of these three classical MCRs intersect at the common N-trityl nitrilium ion intermediate, whose predictable reactivity can be exploited towards chemoselective transformations.

An efficient Ugi‐type three‐component reaction (U‐3CR) for the synthesis of pipecolic amides is reported. The U‐3CR between electronically diverse isocyanides, carboxylic acids and 4‐substituted Δ1‐piperideines proceeds in a highly diastereoselective fashion. The Δ1‐piperideines are obtained by NCS‐mediated oxidation of the corresponding 4‐substituted piperidines, which in turn are generated by an efficient two‐step procedure involving the alkylation of 4‐picoline and subsequent catalytic hydrogenation of the pyridine ring. We demonstrate the utility of this U‐3CR, in combination with the convertible isocyanide 2‐bromo‐6‐isocyanopyridine, in the synthesis of the anticoagulant argatroban.