The present invention relates to an iridium-based catalyst compound for hydrogenating reducible moieties, especially imines and iminiums, the catalyst compounds being defined by the formulas: where ring B is either itself polycyclic, or ring B together with R is polycyclic. The catalysts of the invention are particularly effective in reductive amination procedures
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which involve the in situ generation of the imine or iminium under reductive hydrogenative conditions.
A new catalytic method for the direct alkylation of allylic C(sp3)–H bonds from unactivated alkenes via synergistic organo- and photoredoxcatalysis is described. The transformation achieves an efficient, redox-neutral synthesis of homoallylamines with broad functional group tolerance, under very mild reaction conditions. Mechanistic investigations indicate that the reaction proceeds through the N-centered
Asymmetric Reduction of Imines with Trichlorosilane, Catalyzed by Sigamide, an Amino Acid-Derived Formamide: Scope and Limitations<sup>†</sup>
作者:Andrei V. Malkov、Kvetoslava Vranková、Sigitas Stončius、Pavel Kočovský
DOI:10.1021/jo900561h
日期:2009.8.21
nonaromatic ketones 1−5, in which the steric difference between the alkyl groups R1 and R2 is sufficient. Simple nitrogen heteroaromatics (8a,b,d) exhibit low enantioselectivities due to the competing coordination of the reagent but increased steric hindrance in the vicinity of the nitrogen (8c,e) results in a considerable improvement. Cyclic imines 32d-d exhibited low to modest enantioselectivities.
Cobalt-Catalyzed Chelation-Assisted Alkylation of Arenes with Primary and Secondary Alkyl Halides
作者:Naohiko Yoshikai、Ke Gao、Takeshi Yamakawa
DOI:10.1055/s-0033-1338658
日期:——
center to the alkylhalide to form the corresponding alkyl radical, which has a finite lifetime before it undergoes C–C bond formation. Cobalt–N-heterocyclic carbene catalytic systems have been developed for chelation-assisted ortho-alkylation of aromatic compounds with alkylhalides. Aryl imines can be selectively monoalkylated at room temperature by various primary or secondary alkyl chlorides or
Polycyclization Enabled by Relay Catalysis: One-Pot Manganese-Catalyzed C−H Allylation and Silver-Catalyzed Povarov Reaction
作者:Shi-Yong Chen、Qingjiang Li、Xu-Ge Liu、Jia-Qiang Wu、Shang-Shi Zhang、Honggen Wang
DOI:10.1002/cssc.201700452
日期:2017.6.9
is described for the one‐pot synthesis of polycyclic products by a formal [3+2] and [4+2] cycloadditionreaction cascade. A manganese(I) complex catalyzed the first example of directed C−H allylation with allenes, setting the stage for an in situ Povarov cyclization catalyzed by silver(I). The reaction proceeds with high bond‐forming efficiency (three C−C bonds), broad substrate scope, high regio‐ and
在这项研究中,描述了一种基于Mn I / Ag I的中继催化过程,用于通过正式的[3 + 2]和[4 + 2]环加成反应级联来单锅合成多环产物。锰(I)配合物催化了与丙二烯直接进行CH烯丙基化的第一个例子,为银(I)催化原位Povarov环化奠定了基础。该反应以高键形成效率(三个C键),广泛的底物范围,高的区域和立体选择性以及100%的原子经济性进行。