Synthesis of Pyrrolidines and Piperidines via Palladium-Catalyzed Coupling of Vinylic Halides and Olefinic Sulfonamides

Tandem intramolecular cyclisation/1,3-aryl shift in N-(4,4-diethoxybutyl)-1-arylmethanimines (Kazan reaction): synthesis of 3-benzylidene-1-pyrrolines

“…18 However, very few of these methods allow for simultaneous intramolecular C-N bond formation and intermolecular formation of a carbon-carbon bond. [19][20][21][22] Existing methods require harsh reaction conditions or toxic or expensive reagents, such as Pd complexes. 23 There is the only example of synthesis of a-substituted pyrrolidine via reaction of 1-(4-oxobutyl)urea derivative with thiophenol in acidic media.…”

Pyrrolidine and Piperidine Formation via Copper(II) Carboxylate Promoted Intramolecular Carboamination of Unactivated Olefins: Diastereoselectivity and Mechanism.

“…No ipso (1,5-addition) substitution of the radical onto the aromatic ring was observed. Mixtures of ipso (1,5) addition products and direct (1,6) addition products along with the direct reduction products have previously been observed in the intramolecular radical reactions of N-arylsulfonyl-2-halomethyl piperidines (AIBN, HSnBu 3 , PhH, reflux), and in many instances, the ipso product predominates. 40-44 It has previously been observed, however, that the propensity for direct addition versus ipso substitution in the intramolecular addition reactions of carbon radicals to aromatic rings is highly dependent on the structure of the substrate.…”

“…46 No reaction occurred under the same conditions but in the absence of Cu(OAc) 2 . (6) It should be noted that carbon radicals do react rapidly with copper(II) salts to form organocopper(III) intermediates. 38 This process might be reversible for primary carbon radicals under our reaction conditions.…”

Bis[tri(o-tolyl)phosphine]palladium

“…38 Increased yields were observed when sulfonamides were employed. 39 The mechanism is proposed to involve a nucleophilic attack of the amide to a π-allylpalladium complex (Scheme 3). O-Homoallyl hydroxylamines can also be transformed to isoxazolidine adducts.…”