206127-25-5Relevant articles and documents
Ethynyltributyltin - A synthetic equivalent for acetylene, aryl, acyl and halogeno alkynes in [4+2] cycloadditions
Sauer, Juergen,Heldmann, Dieter K.
, p. 2549 - 2552 (1998)
Ethynyltributyltin 2 cycloadds to 5-phenyl-1,2,4-triazine-3-carboxyclic acid methyl eater I to furnish mainly 4-tributylstannyl-6-phenyl-pyridine-2- carboxyclic acid methyl ester 3a besides a small amount of the 3- tributylstannyl isomer 3b. The tributyltin substituent of pyridine 3a can be replaced by Pd-catalyzed acylation and arylation, by halogenation and protonation to yield functionalized pyridines 4 - 7, which are not available by direct cycloaddition of the corresponding alkynes.
Scope and limitation for FeSO4-mediated direct arylation of heteroarenes with arylboronic acids and its synthetic applications
Komeyama, Kimihiro,Nagao, Yuya,Abe, Manabu,Takaki, Ken
, p. 301 - 313 (2014/03/21)
FeSO4-mediated direct arylation of heteroarenes with arylboronic acids in the presence of K2S2O8 has been developed. A slow addition of an aqueous solution of an iron complex was crucial in the arylation. Scope and limitation of the heteroarenes and arylboronic acids are discussed. Furthermore, the direct arylation was applied to the formal total synthesis botryllazine B and sodium channel inhibitor.
Mn(III)-mediated formal [3+3]-annulation of vinyl azides and cyclopropanols: A divergent synthesis of azaheterocycles
Wang, Yi-Feng,Toh, Kah Kah,Ng, Eileen Pei Jian,Chiba, Shunsuke
supporting information; experimental part, p. 6411 - 6421 (2011/06/19)
Mn(III)-mediated formal [3+3]-annulation has been developed using readily available vinyl azides and cyclopropanols with a wide range of substituents. Vinyl azides were successfully applied as a three-atom unit including one nitrogen to prepare pyridines and σ-lactams by the reactions with monocyclic cyclopropanols as well as to construct 2-azabicyclo[3.3.1] and 2-azabicyclo[4.3.1] frameworks with bicyclic cyclopropanols, bicyclo[3.1.0]hexan-1-ols, and bicyclo[4.1.0]heptan-1-ols. These reactions were initiated by a radical addition of β-carbonyl radicals, generated by the one-electron oxidation of cyclopropanols with Mn(III), to vinyl azides to give iminyl radicals, which cyclized with the intramolecular carbonyl groups. In addition, application of the present methodology to a synthesis of the quaternary indole alkaloid, melinonine-E, was accomplished.