Pd(0)-catalyzed allylic alkylation/Heck coupling in domino sequence
摘要:
A new molecular queuing process has been achieved, in which a single Pd-based catalytic system promotes two unrelated, sequential catalytic cycles in chronologically distinct order. This study demonstrates also that allylic alkylations can be catalyzed by the Herrmann's phosphapalladacycle, a result that further supports the involvement of a Pd(0) species in its mechanism of action. (C) 2001 Elsevier Science Ltd. All rights reserved.
γ- and δ-Lactams through Palladium-Catalyzed Intramolecular Allylic Alkylation: Enantioselective Synthesis, NMR Investigation, and DFT Rationalization
作者:Xavier Bantreil、Guillaume Prestat、Aitor Moreno、David Madec、Peter Fristrup、Per-Ola Norrby、Paul S. Pregosin、Giovanni Poli
DOI:10.1002/chem.201001300
日期:2011.3.1
give γ‐ and δ‐lactams has been studied in the presence of chiral ligands. Ligand (R)‐3,5‐tBu‐MeOBIPHEP (MeOBIPHEP=6,6’‐dimethoxybiphenyl‐2,2‐diyl)bis(diphenylphosphine)) afforded the best results and allowed the cyclization reactions to take place in up to 94:6 enantiomeric ratio. A model Pd–allyl complex has been prepared and studied through NMR spectroscopic analysis, which provided insight into the
在手性配体存在下,对钯催化的不饱和酰胺的分子内烯丙基烷基化反应生成γ-和δ-内酰胺进行了研究。配体(R)-3,5- t Bu-MeOBIPHEP(MeOBIPHEP = 6,6'-二甲氧基联苯-2-2,2-二基)双(二苯基膦))提供了最佳结果,并使环化反应可在多达94个条件下进行:6对映体比率。制备了钯-烯丙基复合物模型,并通过NMR光谱分析进行了研究,该分析提供了对观察到的对映体比率负责的过程的见解。DFT研究用于表征非对映异构反应途径。计算出的能量差与实验观察到的对映体比率非常吻合。
Palladium-catalyzed pseudo-domino cyclizations
作者:Sébastien Lemaire、Guillaume Prestat、Giuliano Giambastiani、David Madec、Barbara Pacini、Giovanni Poli
DOI:10.1016/s0022-328x(03)00621-1
日期:2003.12
A new type I palladium-catalyzed pseudo-domino process is developed, in which a single Pd-based catalytic system promotes two mechanistically unrelated, sequential catalytic cycles in chronologically distinct order. Suitable precursors undergo an allylic alkylation and a Heck coupling in sequence, affording polycondensed pyrrolidone derivatives. Depending on the starting precursors, intra/inter or
Synthesis of substituted γ- and δ-lactams based on titanocene(<scp>iii</scp>)-catalysed radical cyclisations of trichloroacetamides
作者:Faïza Diaba、Enrique Gómez-Bengoa、Juan M. Cuerva、Josep Bonjoch、José Justicia
DOI:10.1039/c6ra12180b
日期:——
A new procedure for the synthesis of γ- and δ-lactams based on a Cp2TiCl-catalysed cyclisation of trichloroacetamides under mild reaction conditions is reported. Theoretical studies supported the observed regioselectivity in the cyclisations and the mechanism involved in the dehalogenation process.