23985-06-0Relevant articles and documents
Synthetic application of sequential palladium-catalyzed allylic acetate alkylation and michael addition carbocyclization: Synthesis of (±)-dihydroerythramine
Jousse-Karinthi, Celine,Riche, Claude,Chiaroni, Angele,Desmaele, Didier
, p. 3631 - 3640 (2001)
A new synthetic route to aromatic Erythrina alkaloids is reported. (Nitromethyl)arene 3 underwent a palladium-catalyzed annulation reaction with allylic acetate 11 to provide nitro esters 12a and 12b by an (η3-allyl)palladium complex alkylation/Michael addition domino sequence. Reduction of the nitro group of 12a, followed by cyclization of the resulting amino group on the acetate appendage, afforded the bicyclic lactam 29. Two-carbon elongation at the nitrogen atom of 29 by hetero Michael addition of vinyl phenyl sulfoxide, followed by Pummerer-type cyclization, gave cis-11-phenylthioerythrinan-8-one (32a, 32b) along with the rearranged lactam 34. Reductive desulfurization at C-11, and oxidative cleavage of the C-3 exocyclic double bond afforded the 15,16-(methylenedioxy)erythrinan-3,8-dione (42). Reduction of the C-3 carbonyl group and methylation of the resulting alcohol afforded hexahydrocrystamidine (44), which was further reduced by aluminum hydride to give (±)-dihydroerythramine (9).
The six-membered annulation reaction involving sequential palladium-catalyzed allylic alkylation and Michael addition: Scope and limitations
Jousse-Karinthi, Céline,Zouhiri, Fatima,Mahuteau, Jacqueline,Desma?le, Didier
, p. 2093 - 2099 (2003)
The palladium-catalyzed condensation of a variety of active methylene compounds with methyl 6-acetoxymethyl-hepta-2,6-dienoate was investigated. The six-membered adducts resulting from a η3 palladium complex alkylation-Michael addition sequence were obtained with moderate to good yields. In some cases, further evolution of the primary adduct was observed. The process has been expanded to access nitrogen heterocycles by using sodium p-toluenesulfonamide as the nucleophilic partner.
Iron-Catalyzed Tertiary Alkylation of Terminal Alkynes with 1,3-Diesters via a Functionalized Alkyl Radical
Tian, Ming-Qing,Shen, Zhen-Yao,Zhao, Xuefei,Walsh, Patrick J.,Hu, Xu-Hong
supporting information, p. 9706 - 9711 (2021/03/19)
Direct oxidative C(sp)?H/C(sp3)?H cross-coupling offers an ideal and environmentally benign protocol for C(sp)?C(sp3) bond formations. As such, reactivity and site-selectivity with respect to C(sp3)?H bond cleavage have remained a persistent challenge. Herein is reported a simple method for iron-catalyzed/silver-mediated tertiary alkylation of terminal alkynes with readily available and versatile 1,3-dicarbonyl compounds. The reaction is suitable for an array of substrates and proceeds in a highly selective manner even employing alkanes containing other tertiary, benzylic, and C(sp3)?H bonds alpha to heteroatoms. Elaboration of the products enables the synthesis of a series of versatile building blocks. Control experiments implicate the in situ generation of a tertiary carbon-centered radical species.
Organocatalyzed Tsuji-Trost reaction: a new method for the closure of five- and six-membered rings
Vulovic, Bojan,Bihelovic, Filip,Matovic, Radomir,Saicic, Radomir N.
scheme or table, p. 10485 - 10494 (2010/02/28)
A combination of organotransition metal catalysis and organocatalysis allows for Tsuji-Trost 5-exo- and 6-exo-cyclizations of aldehydes. This transformation can also be accomplished as a catalytic asymmetric reaction, which affords vinylcyclopentane deriv
