Investigation of the Mechanism of C(sp<sup>3</sup>)−H Bond Cleavage in Pd(0)-Catalyzed Intramolecular Alkane Arylation Adjacent to Amides and Sulfonamides
作者:Sophie Rousseaux、Serge I. Gorelsky、Benjamin K. W. Chung、Keith Fagnou
DOI:10.1021/ja103081n
日期:2010.8.11
reactivity of C(sp(3))-H bonds adjacent to a nitrogen atom can be tuned to allow intramolecular alkane arylation under Pd(0) catalysis. Diminishing the Lewis basicity of the nitrogen lone pair is crucial for this catalytic activity. A range of N-methylamides and sulfonamides react exclusively at primary C(sp(3))-H bonds to afford the products of alkane arylation in good yields. The isolation of a Pd(II) reaction
A Pd-catalyzed, boron ester-mediated, reductive cross-coupling of two aryl halides to synthesize tricyclic biaryls
作者:Zhilong Chen、Xiaodong Wang
DOI:10.1039/c7ob01237c
日期:——
Tricyclic biaryls are important scaffold structures in many natural products and lead compounds in drug discovery. The formation of a biaryl unit is often the key step for the synthesis of tricyclic biaryls. Despite significant progress toward the synthesis of biaryl compounds in recent years, the direct cross-coupling of two different aryl halides is still challenging and robust methods are lacking
Oxidation during reductive cyclisations using Bu3SnH
作者:W.Russell Bowman、Harry Heaney、Benjamin M. Jordan
DOI:10.1016/s0040-4020(01)96061-2
日期:1991.1
Reductivecyclisations using Bu3SnH include an “oxidation” step if the removal of an acidic proton from the intermediate cyclised radical, by Bu3SnH acting as a base, is favourable. A “pseudo” SRN1 mechanism is proposed.
如果通过Bu 3 SnH作为碱从中间环化自由基中除去酸性质子是有利的,则使用Bu 3 SnH进行的还原环化包括一个“氧化”步骤。提出了一种“伪” S RN 1机制。
Potassium <i>tert</i>-Butoxide Promoted Intramolecular Arylation via a Radical Pathway
作者:Daniela Sustac Roman、Yoko Takahashi、André B. Charette
DOI:10.1021/ol201160s
日期:2011.6.17
Potassium tert-butoxide mediated intramolecular cyclization of aryl ethers, amines, and amides was efficiently performed under microwave irradiation to provide the corresponding products in high regioisomeric ratios. The reaction proceeds via single-electron transfer to initiate the formation of an arylradical, followed by a kinetically favored 5-exo-trig and subsequent ring expansion.