35285-61-1Relevant academic research and scientific papers
Palladium-Catalyzed Intramolecular Addition of Amines to Acetylenes. Synthesis of Cyclic Imines
Fukuda, Yukitoshi,Matsubara, Seijiro,Utimoto, Kiitiro
, p. 5812 - 5816 (2007/10/02)
Intramolecular aminopalladation of alkynylamines gave intermediary alkenylpalladium compounds that hydrolyzed and isomerized to thermodynamically stable cyclic imines.Treatment of 3-alkynylamines with a catalytic amount of PdCl2(MeCN)2 gave exclusively 1-
Preparation of 2,3,4,5-tetrahydropyridines from 5-alkynylamines under the catalytic action of gold(III) salts
Fukuda,Utimoto
, p. 975 - 978 (2007/10/02)
Intramolecular addition of amine to carbon-carbon triple bonds in 5-alkynylamines produces 2,3,4,5-tetrahydropyridines under the catalytic action of an aurate salt. Some venom components of various ant species are synthesized by the application of this re
Stereoselective Syntheses of cis-2-Alkyl-6-methylpiperidines
Ryckman, David M.,Stevens, Robert V.
, p. 4274 - 4279 (2007/10/02)
Syntheses in the pine alkaloid family, the fire ant venom series, and continued studies in the Poranthera species are presented.Reaction of 5-lithio-2-pentanone-2,2-dimethylpropylene ketal or the corresponding dialkylcuprate compound with carboxylic acid derivatives gives selectively protected 1,5-dicarbonyl compounds.After reductive amination of the newly formed ketone function, acidic hydrolysis of the cyclic ketal gives 6-alkyl-2-methyl-3,4,5,6-tetrahydropyridines.Stereoselective reduction of the imine function affords cis-2,6-disubstituted piperidines.Examplesof this approach include syntheses of dihydropinidine from Pinus sabiniana and the fire ant venoms cis-2-methyl-6-undecylpiperidine and 2-methyl-6-undecyl-3,4,5,6-tetrahydropyridine from Solenopis geminata and S. xyloni.A preliminary report on an approach to porantherilidine, from Poranthera corymbosa, is described.
Highly Regioselective α-Addition of Alkynyl and Alkenyl Grignard Reagents to 1-Alkoxycarbonylpyridinium Salts and Its Application to Synthesis of 1-Azabicycloalkanes and (+/-)-Solenopsin A
Yamaguchi, Ryohei,Nakazono, Yutaka,Matsuki, Toshitsugu,Hata, Ei-ichiro,Kawanisi, Mituyosi
, p. 215 - 222 (2007/10/02)
Nucleophilic addition of a variety of alkynyl and alkenyl Grignard reagents to 1-methoxycarbonylpyridinium chloride takes place at the α-position in a highly regioselective manner to give 2-substituted 1-methoxycarbonyl-1,2-dihydropyridines exclusively, while, with alkyl Grignard reagents, a lack of the regioselectivity is observed.These results may be explained by the HSAB principle.The high α-regioselectivity is preserved in the cases of 2-substituted pyridines as well, giving 2,6-disubstituted 1,2-dihydropyridines exclusively, which can be transformed stereoselectively into cis- and trans-2,6-dialkylated piperidines.These highly regioselective α-alkynylations of 1-methoxycarbonylpyridinium salts are exploited in synthesis of 1-azabicycloalkanes as well as (+/-)-solenopsin A.
SYNTHESIS OF cis AND trans-2,6-DIALKYLATED PIPERIDINES THROUGH HIGHLY REGIOSELECTIVE Α-ALKYNYLATION OF PYRIDINIUM SALTS AND ITS APPLICATION TO SYNTHESIS OF (+)-SOLENOPSINE A
Nakazono, Yutaka,Yamaguchi, Ryohei,Kawanisi, Mituyosi
, p. 1129 - 1132 (2007/10/02)
Reactions of N-methoxycarbonyl-2-alkylpyridinium salts with alkynyl Grignard reagents give exclusively 2,6-disubstituted 1,2-dihydropyridines, from which cis- and trans-2,6-dialkylated piperidines can be derived selectively.Consequently, (+)-solenopsine A is efficiently synthesized by this sequence.
Organoaluminum-Promoted Beckmann Rearrangement of Oxime Sulfonates
Maruoka, Keiji,Miyazaki, Tohru,Ando, Mamoru,Matsumura, Yasushi,Sakane, Soichi,et al.
, p. 2831 - 2843 (2007/10/02)
The Beckmann rearrangement of oxime sulfonates with simultaneous nucleophilic trapping of the intermediary iminocarbocation by organoaluminum reagents is described.This process provides a new and highly efficient route to imino thioethers, imino selenoethers, imino nitriles, and α-alkylated amines starting from oxime sulfonates by the use of dialkylaluminum thiolates, selenolates, diethylaluminum chloride-trimethylsilyl cyanide, and trialkylaluminum-diisobutylaluminum hydride systems, respectively.The present organoaluminum-promoted Beckmann rearrangement of oxime sulfonates has been successfully applied to the synthesis of naturally occuring alkaloids, pumiliotoxin C and solenopsin A and B, in stereoselective fashion.Moreover, α,α-dialkylation of amines can be realized by the successive treatment of oxime sulfonates with trialkylaluminum followed by allylic or propargylic Grignard reagents in synthetically useful yields.
STEREOSELECTIVE SYNTHESES OF SOLENOPSIN A AND B
Matsumura, Yasushi,Maruoka, Keiji,Yamamoto, Hisashi
, p. 1929 - 1932 (2007/10/02)
Effective and convenient syntheses of solenopsin A and B have been developed which involve the Beckmann rearrangement-alkylation reaction promoted by organoaluminum reagents and a new stereoselective reduction of imino functional group.
