Carbonylative coupling of organozinc reagents in the presence and absence of aryl iodides: synthesis of unsymmetrical and symmetrical ketones
作者:Richard F. W. Jackson、Debra Turner、Michael H. Block
DOI:10.1039/a606394b
日期:——
The utility of the palladium(0) catalysed reaction of the
iodoalanine-derived organozinc reagent 6a with functionalised
aryl iodides, under a carbon monoxide atmosphere, to give
protected 4-aryl-4-oxo α-amino acids 8, is illustrated by
a short synthesis of L-kynurenine 4. Treatment of
functionalised organozinc reagents with catalytic
tetrakis(triphenylphosphine)palladium(0) under an atmosphere of
carbon monoxide in the absence of any electrophile leads to the
formation of symmetrical functionalised ketones 9 in good yields.
This reaction is illustrated by a one-step synthesis of protected
(2S,6S)-4-oxo-2,6-diaminopimelic acid 9a from
commercially available compounds. It has been established that
adventitious molecular oxygen plays a key role in the formation
of the symmetrical ketones 9, and that rigorous exclusion of
oxygen can result in substantially higher yields of ketones 8 in
the cross-coupling with some aromatic iodides.
α-Oxo-Ketenimines from Isocyanides and α-Haloketones: Synthesis and Divergent Reactivity
作者:Mathias Mamboury、Qian Wang、Jieping Zhu
DOI:10.1002/chem.201703458
日期:2017.9.18
β-Hydride elimination at will: Reaction of α-haloketones with isocyanides in the presence of a catalytic amount of Pd(OAc)2 afforded α-oxo-ketenimines that can be further converted to 5-aminopyrazoles, tetrazole, β-keto amidines and enaminone in good to excellent yields.
Stoichiometric Reactions of Acylnickel(II) Complexes with Electrophiles and the Catalytic Synthesis of Ketones
作者:Alexander C. Wotal、Ryan D. Ribson、Daniel J. Weix
DOI:10.1021/om5004682
日期:2014.10.27
While reactions with bromobenzene formed complex mixtures of ketones, reactions with α-chloroethylbenzene were highly selective for the cross-ketone product. Reactions with iodooctane and bromooctane also produced the cross-ketone product, but in intermediate yield and selectivity. In most cases the presence or absence of a chemical reductant (zinc) had only a small effect on the selectivity of the
酰基镍 (II) 配合物在形成酮的交叉亲电偶联 (XEC) 反应中具有突出的特征,但尚未系统地研究它们的反应性。我们在这里展示了我们对酰基镍 (II) 配合物与一系列碳亲电子试剂的反应性的研究。溴苯、α-氯乙苯、溴辛烷和碘辛烷与 (dtbbpy)Ni II (C(O)C 5 H 11 )(Br) ( 1b ) 和 (dtbbpy)Ni II (C(O)tolyl)(Br) 反应( 1c)形成多种有机产品。虽然与溴苯的反应形成复杂的酮混合物,但与 α-氯乙苯的反应对交叉酮产物具有高度选择性。与碘辛烷和溴辛烷的反应也产生交叉酮产物,但产率和选择性中等。在大多数情况下,化学还原剂(锌)的存在与否对反应的选择性只有很小的影响。1c与碘辛烷的偶联(产率 60%)转化为催化反应,即溴芳烃与伯溴烷烃的羰基化偶联(六个实施例,平均产率 60%)。
Asymmetric synthesis of chiral spiroacetals from chiral diketodisulfoxides: 2,8-dimethyl-1,7-dioxaspiro [5,5] undecane.
作者:Guy Solladié、Nathalie Huser
DOI:10.1016/s0957-4166(00)86181-9
日期:1994.1
(2RdS,8R) and (2S,6R,8S) 2,8-dimethyl-1,7-dioxaspiro [5,5] undecane have been prepared by asymmetric reduction of a diketodisulfoxide intermediate.
Preparation of polyfunctional ketones by a cobalt(II) mediated carbonylation of organozinc reagents
作者:A. Devasagayaraj、P. Knochel
DOI:10.1016/0040-4039(95)01802-o
日期:1995.11
Functionalized organozinc halides can be efficiently carbonylated under atmospheric pressure in the presence of cobalt(II) bromide in THF:NMP leading to polyfunctional symmetrical ketones in 56–80 % yield.