The aza-Morita-Baylis-Hillman reactions of aldimines 2 with several activated conjugated dienes were found to proceed smoothly in DMF in the presence of 3-hydroxyquinuclidine (HQD). Imines 2 reacted with 1-(p-toluenesulfonyl)-1,3-butadiene (3), methyl 2,4-pentadienoate (6), hexa-3,5-dien-2-one (7), and 1-phenylpenta-2,4-dien-1-one (8) to afford adducts 4, 13, 14, and 15, respectively. While products 4, 13, and 15 were formed as E,Z mixtures, adducts 14 were obtained as essentially pure E-isomers. Cyclization of the E-isomers of the products derived from the dienyl sulfone 3 and the dienoate ester 6 occurred via intramolecular conjugate addition under base-catalyzed conditions to afford functionalized piperidines 5 and 16, respectively. The aza-Morita-Baylis-Hillman reaction and subsequent cyclization of the imine 2a with 3 were also carried out as a one-pot reaction, while the reaction mixture was simultaneously irradiated at 300 nm to effect the photoisomerization of the unreactive Z-adduct of the corresponding 4 to the more reactive E-isomer.

[reaction: see text] Aldimines 2 underwent Morita-Baylis-Hillman reaction with 1-(p-toluenesulfonyl)-1,3-butadiene (3) in the presence of 3-hydroxyquinuclidine (HQD) to afford adducts 4. The E-isomers of the products cyclized to the corresponding functionalized piperidines 8 under base-catalyzed conditions. Simultaneous equilibration of (E)-4 and (Z)-4 was effected by photoisomerization to improve the efficiency of the cyclization.

Amines Q 0120Morita-Baylis-Hillman Reaction and Cyclization of 1-(p-Toluenesulfonyl)-1,3-butadiene with Aldimines. -The title reaction fails with (toluenesulfonyl)butadienes which are sterically more hindered than compound (II), e.g. the 2-, 3-, and 4-methyl-substituted analogues. -(BACK*, T. G.; RANKIC, D. A.; SORBETTI, J. M.; WULFF, J. E.; Org. Lett. 7 (2005) 12, 2377-2379; Dep. Chem., Univ. Calgary, Calgary, Alberta T2N 1N4, Can.; Eng.) -Nuesgen 44-088

Sulfonamides Q 0560Aza-Morita-Baylis-Hillman Reactions and Cyclizations of Conjugated Dienes Activated by Sulfone, Ester, and Keto Groups. -In the presence of hydroxyquinuclidine, aromatic aldimines smoothly undergo aza-Morita-Baylis-Hillman reaction with activated dienes like (II), (VIII) and (XII). Treatment of the (E)-adducts (III) and (IX) with bases results in formation of functionalized piperidines. The keto analogues generated form dienones, however, do not undergo cyclization. -(SORBETTI, J. M.; CLARY, K. N.; RANKIC, D. A.; WULFF, J. E.; PARVEZ, M.; BACK*, T. G.; J. Org. Chem. 72 (2007) 9, 3326-3331; Dep. Chem., Univ. Calgary, Calgary, Alberta T2N 1N4, Can.; Eng.) -Jannicke 36-071