Allyl isocyanide synthesis

The reaction of an isocyanide containing an acidic hydrogen with copper(I) oxide and an activated olefin or a ketone [Eq. (123)] provides a synthesis of either pyrrolines or oxazolines, respectively (251,252). Addition of allyl bromide gave the coupling product with the allyl carbanion derived from allyl isocyanide. Oxazolines are obtained in yields as high as 957o> not pyrrolines because of competing dimerization... 

Van Leusen and Possel described the use of mono-substituted tosylmethyl isocyanides (TosCHRN=C R = alkyl, benzyl, allyl) in the synthesis of 4,5-substituted oxazoles. For example, 4-ethyl-5-phenyloxazole (8) was prepared in 82% yield by refluxing a-tosylpropyl isocyanide (7) and benzaldehyde for 1 hr with 1.5 equivalent of K2CO3 in MeOH. 

Imidates, rearrangement of, 14, 1 Imines, additions of allyl, allenyl, propargyl stannanes, 64, 1 additions of cyanide, 70, 1 as dienophiles, 65, 2 synthesis, 70, 1 Iminium ions, 39, 2 65, 2 Imino Diels-Alder reactions, 65, 2 Indoles, by Nenitzescu reaction, 20, 3 by reaction with TosMIC, 57, 3 Ionic hydrogenation, 71, 1 Isocyanides, in the Passerini reaction, 65, 1... 

The synthon of the a-acrylate anion is available from a secondary a-keto carboxamide by the Shapiro reaction. The secondary a-ketoamide trisylhydrazones ate ptepar in a one-pot synthesis by reaction of the isocyanides with acid chloride, water and trisylhydrazine in sequence. In DME solvent, the hydra-zone (103) is smoothly metallated with BuLi to give Ae trianion (KH). Allylation of the trianion (104) gives the hydrazone (105). Alternatively, warming (104) up to room temperature yields the dianion (106) which can be intercepted with several electrophiles (Scheme 23). The adduct (107) is readily transformed into the rran -iodo lactone (108) stereospecifically (equation 56). This chemistry also has been applied to a new synthesis of -lactams (Scheme 24). ... 

The nickel(II) complex 14 is also known as a catalyst for the polymerization of 1,3-butadiene. The versatility of this nickel catalyst was used in the synthesis of butadiene-isocyanide block copolymers [27]. In the so-called change of mechanism block copolymerization, 1,3-butadiene was initially polymerized with 14, yielding a butadiene polymer bearing living 773-allyl-nickel termini (Scheme 20). Addition of terf-butyl isocyanide to this living... 

Isocyano-2-methyl)-propyl-l-]-alkyl-carbonate [(2-Isocyano-2-methyl)-propyl-l-]-alkyl-carbonates (Ip) were developed by Lindhorst in collaboration with Ugi and have been referred to as the Lindhorst isocyanides [64], The synthesis of Ip and its analog are very simple (Scheme 7.44). Commercially available 4,4-dimethyl-2-oxazoline 135 can be deprotonated by "BuLi in anhydrous THF at -78° C and the resulting lithium alcoholate lo is captured with alkyl chloroformate (R = Me, Et, allyl, Bn) to provide 80% of the desired product as colorless crystals or oil (Scheme 7.44). It can be further purified by vacuum distillation. This one-step method offers several advantages (i) it does not involve phosgene or derivatives thereof, (ii) (p-isocyano-ethyl)-alkyl carbonates are stable and can be stored at room temperature, and (iii) it can be employed in a large-scale synthesis. 

---