97580-29-5Relevant academic research and scientific papers
Cobalt-Catalyzed Regioselective Olefin Isomerization under Kinetic Control
Liu, Xufang,Zhang, Wei,Wang, Yujie,Zhang, Ze-Xin,Jiao, Lei,Liu, Qiang
supporting information, p. 6873 - 6882 (2018/05/30)
Olefin isomerization is a significant transformation in organic synthesis, which provides a convenient synthetic route for internal olefins and remote functionalization processes. The selectivity of an olefin isomerization process is often thermodynamically controlled. Thus, to achieve selectivity under kinetic control is very challenging. Herein, we report a novel cobalt-catalyzed regioselective olefin isomerization reaction. By taking the advantage of fine-tunable NNP-pincer ligand structures, this catalytic system features high kinetic control of regioselectivity. This mild catalytic system enables the isomerization of 1,1-disubstituted olefins bearing a wide range of functional groups in excellent yields and regioselectivity. The synthetic utility of this transformation was highlighted by the highly selective preparation of a key intermediate for the total synthesis of minfiensine. Moreover, a new strategy was developed to realize the selective monoisomerization of 1-alkenes to 2-alkenes dictated by installing substituents on the γ-position of the double bonds. Mechanistic studies supported that the in situ generated Co-H species underwent migratory insertion of double bond/β-H elimination sequence to afford the isomerization product. The less hindered olefin products were always preferred in this cobalt-catalyzed olefin isomerization due to an effective ligand control of the regioselectivity for the β-H elimination step.
A Highly Diastereoselective Synthesis of cis-4a-Aryloctahydro-cyclopentapyridine Derivatives through Tandem Radical Cyclization of α-amino Radical Polyene Species
Kano, Shinzo,Yuasa, Yoko,Yokomatsu, Tsutomu,Asami, Kenji,Shibuya, Shiroshi
, p. 2934 - 2939 (2007/10/02)
8a-Aryloxazolocyclopentapyridines (9a-c) were prepared via a route involving radical cyclization of α-acylamino radical polyene species generated by treatment of 4-phenylthiooxazolidin-2-ones (8a-c) with tri-n-butyltin hydride in the presence of azobisisobutyronitrile (AIBN).Conversion of 9a to cis-octahydro-2,5-dimethyl-4a-phenylcyclopentapyridine (19) was successfully achieved via a route involving ring cleavage of the oxazolidinone ring of 9a, oxidation of hydroxymethyl group, and decarbonylation.Keywords - radical cyclization; cyclopentapyridine; α-acylamino radical; α-amino radical-polyene; tandem radical cyclization; decarbonylation
Effect of A-Strain on a Synthesis of cis-Fused 4a-Aryloctahydro-1H-cyclopentapyridine Derivatives through Tandem Radical Cyclisation of an α-Acylamino-Polyene System
Kano, Shinzo,Yuasa, Yoko,Yokomatsu, Tsutomu,Asami, Kenji,Shibuya, Shiroshi
, p. 1717 - 1718 (2007/10/02)
An efficient synthesis of the cis-fused 4a-aryloctahydro-1H-cyclopentapyridine ring system, an analogue of 4a-aryldecahydroisoquinoline, was achieved through a tandem radical approach by cyclisation of free radical-polyene species.
AN EFFICIENT DIASTEREOSELECTIVE SYNTHESIS OF 6-HYDROXY-4a--trans-DECAHYDROISOQUINOLINE
Kano, Shinzo,Yokomatsu, Tsutomu,Nemoto, Hajime,Shibuya, Shiroshi
, p. 1531 - 1534 (2007/10/02)
A high diastereoselective synthesis of 6-hydroxy-4a-aryl-trans-decahydroisoquinoline derivatives was achieved by an application of N-acyliminium ion-induced polyene cyclization procedure.
