co-cyclization of a variety of 1-alkynes (R′CCH) and nitriles (R″CN) to pyridine derivatives is reported. Initial reaction rates as well as chemoselectivity and regioselectivity are markedly influenced by the electron donor—acceptor properties of the R groups on the cyclopentadienyl ring, as well as by the steric and electroniceffects induced by the substituents (R′ and R″) attached to substrates.
性质的由式的催化剂前体显示出研究的[Rh(η 5 -C 5 H ^ 4 R)(C 2 H ^ 4)2 ](RNME 2,吨卜中,Me,是H,Cl,NO 2,报道了在各种1-炔烃(R'CCH)和腈(R''CN)的共环化为吡啶衍生物中的CF 3或COOMe)。初始反应速率以及化学选择性和区域选择性受环戊二烯基环上R基团的电子给体-受体性质以及与之连接的取代基(R'和R'')引起的空间和电子效应的显着影响基材。
A new cyclopentadiene and its use as a ligand for catalytically active rhodium complexes
作者:Mirco Costa、Francisco Santos Dias、Gian Paolo Chiusoli、Gian Luca Gazzola
DOI:10.1016/0022-328x(94)00020-d
日期:1995.2
carbonylation and by elimination of the benzyloxycarbonyl group and double bonds isomerization. The anion of the diacetate readily reacts with transition metal complexes, to give the corresponding cyclopentadienyl derivatives. We describe here some complexes, obtained from [RhCl(L)2}2] [L = CO, C2H4 or 1,5-cyclooctadiene (COD)], which are efficient catalysts for the alkyne-nitrile co-cyclization to pyridines
由丙二酸甲基甲酯与2-丙炔基溴反应,然后钯催化成环的氧化羰基化反应,并消除苄氧羰基和双键,制得4-甲氧基羰基环戊-1,3-二烯-1,2-二乙酸二甲酯。键异构化。二乙酸根的阴离子容易与过渡金属络合物反应,得到相应的环戊二烯基衍生物。我们在这里描述了从[RhCl(L)2 } 2 ] [L = CO,C 2 H 4或1,5-环辛二烯(COD)]获得的一些配合物,它们是炔-腈共环化的有效催化剂生成吡啶并用于苯乙烯和1-己烯的加氢甲酰化。