Synthesis of 2-Arylpiperidines by Palladium Couplings of Aryl Bromides with Organozinc Species Derived from Deprotonation of <i>N</i>-Boc-Piperidine
作者:Iain Coldham、Daniele Leonori
DOI:10.1021/ol801579r
日期:2008.9.1
The organolithium species derived from proton abstraction of N-Boc-piperidine with s-BuLi and TMEDA can be transmetalated to the organozinc reagent, and this organometallic species can be coupled directly with aryl bromides in a Negishi-type reaction using palladium catalysis with the ligand tri-tert-butylphosphine (t-Bu3P-HBF4). The chemistry was applied to a very short synthesis of the alkaloid anabasine
[Co(TPP)]‐Catalyzed Formation of Substituted Piperidines
作者:Marianne Lankelma、Astrid M. Olivares、Bas de Bruin
DOI:10.1002/chem.201900587
日期:2019.4.17
the [Co(TPP)]‐catalyzed formation of useful six‐membered N‐heterocyclic piperidines directly from linear aldehydes is presented herein. The piperidines were obtained in overall high yields, with linear alkenes being formed as side products in small amounts. A DFT study was performed to gain a deeper mechanistic understanding of the cobalt(II)‐porphyrin‐catalyzed formation of pyrrolidines, piperidines
A general and efficient method for heterocyclization involving benzylic C(sp3)–H functionalization enabled by visible light photoredox catalysis to access a wide range of structurally diverse oxygen as well as nitrogen heterocycles up to a gram scale is reported. The potential application of this new methodology is demonstrated by the total synthesis of (−)-codonopsinine and (+)-centrolobine. Herein
Nickel‐Catalyzed Thermal Redox Functionalization of C(sp
<sup>3</sup>
)−H Bonds with Carbon Electrophiles**
作者:Yuxin Gong、Lei Su、Zhaodong Zhu、Yang Ye、Hegui Gong
DOI:10.1002/anie.202201662
日期:2022.5.23
Under thermal conditions, nickel-catalyzed C(sp3)−Hredoxfunctionalization with carbonelectrophiles has been advanced to forge value-added C(sp3)−C bonds in good to excellent efficiency. This method emphasizes the use of external Zn as reductant and di-tert-butyl peroxide as an oxidant and shows remarkable compatibility with Ni-catalysis.
Copper Cyanide-Catalyzed Palladium Coupling of <i>N</i>-<i>tert</i>-Butoxycarbonyl-Protected α-Lithio Amines with Aryl Iodides or Vinyl Iodides
作者:R. Karl Dieter、ShengJian Li
DOI:10.1021/jo970985b
日期:1997.10.1
Treatment of (alpha-aminoalkyl)lithium reagents with aryl iodides in the presence of catalytic amounts of CuCN and PdCl2(PPh3)(2) or [(p-MeOC6H4)(3)P](4)Pd affords 2-aryl substituted amines in modest to good yields. The yields can be improved by use of softer ligands such as AsPh3 and SbPh3 or by use of bis(diphenylphosphino)ferrocene (dppf). Coupled products are obtained with electron-rich aryl iodides (XArI, X = Me, OMe), and the reaction fails with electron-poor aryl iodides (XArI, X = NO2, CO2Li). Treatment of the (alpha-aminoalkyl)lithium reagents with vinyl iodides and Pd(0)/dppf/CuCN afforded the coupling products in low to modest yields.