Propargylation imides

L. E, Overman, Acc. Chem. Res. 13, 218-223 (1980 Allylic and Propargylic Imidic Esters in Organic Synthesis". 

A comparison of reaction conditions has shown that palladium catalysis is particularly effective in achieving complete chiral transfer (eq 3). Propargylic imidates also rearrange when heated in refluxing xylene. The initially formed allene undergoes a series of tautomerizations so that amino 1,3-dienes are the ultimate products (eq 4). These dienes have found use in the Diels-Alder reaction. ... 

The synthetic potential of alkenylzirconium complexes is partially due to the fact that the hydrozirconation of alkynes can be carried out in the presence of some synthetically useful functional groups such as halide [80,153, 211, 212], acetals, amides, imides, carbamates, sulfides [186], ester, cyano [95, 213] and chiral propargyl amino functionalities [214]. 

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... 

Cyclization reactions of a-acyliminium ions with allyl- and propargyl-silanes constitute a useful method for the preparation of various N-bridgehead bicyclic systems. Thus, from a reaction of hydroxylactams 107 and 108, the azaazulenes 109 and 110 were obtained in excellent yields (83TL1407). Similarly, the keto amide 112 was obtained from the imide 111 by reduction to the corresponding hydroxylactam and acid-catalyzed cyclization (84JCS(P1)2477). 

Dicohalt hexacarhonyl-coordinated propargyl ethers also combine with imide horon enolates through a kinetic resolution of the rapidly interconverting propargylic cation isomers to afford a 92 8 mixmre of isomers at the p-center in 80% yield (eq 17). Stereocontrol of the a-center is 97 3. ... 

Thermal rearrangement of imidate esters of propargylic alcohols leads via N-acylaminoallenes to N-acyl-1-amino-1,3-dienes or /V-acyl-2-amino-1,3-dienes, depending upon the substitution of the propargylic alcohol (Scheme 27). ... 

The reaction has also been used to make cyclopentenes by adding silylated propargyl cations to alkenes addition to a titanium imide complex has also been reported. ... 

In 2004, Louie reported a convenient route to prepare CO2 adducts by depro-tonating the imidazolium salts with potassium tert-butoxide under an atmosphere of C02. These are convenient free NHC precursors, also used in the preparation of [(NHC)M] complexes (see Chapters 1 and 2 for further details). Alternatively, NHC-CO2 adducts have been used in several CO2 fixation reactions. Lu tracked the progress of the coupling of CO2 with epoxides in imid-azolium-based ionic liquids by in situ IR monitoring with various epoxides. Later, Ikariya and Tommassi extended the substrate scope to propargylic alcohols and aziridines under milder conditions (Scheme 14.26). 

Furthermore, the method was extended to an intramolecular [2-1-2]-photocycloaddition of imides linked to an allyhc alcohol or a propargyl alcohol by a chiral tether (Scheme 22). Interestingly, when l-valinol was used as a chiral auxihary, a high diastereoselectivity was also observed for the cycloaddition of the unsaturated anhydride with an alkenyl or an alkynyl unit. 

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