Palladium-Catalyzed Direct C−H Arylation of <i>N</i>-Iminopyridinium Ylides: Application to the Synthesis of (±)-Anabasine
作者:Alexandre Larivée、James J. Mousseau、André B. Charette
DOI:10.1021/ja710073n
日期:2008.1.1
Palladium-catalyzed direct C-H arylation of N-iminopyridinium ylides provides a powerful and versatile method for the synthesis of functionalized piperidines in good yields. Chemoselective functionalization of the pyridinium ring in the presence of a pyridine substituent is possible as exemplified by the expedient synthesis of anabasine in 61% overall yield over three steps.
Alkynyl Thioethers in Gold-Catalyzed Annulations To Form Oxazoles
作者:Raju Jannapu Reddy、Matthew P. Ball-Jones、Paul W. Davies
DOI:10.1002/anie.201706850
日期:2017.10.16
regioselective, and convergent access to densely functionalized oxazoles is realized in a functional-group tolerant manner using alkynylthioethers. Sulfur-terminated alkynes provide access to reactivity previously requiring strong donor-substituted alkynes such as ynamides. Sulfur does not act in an analogous donor fashion in this gold-catalyzed reaction, thus leading to complementary regioselective outcomes
The gold–acid‐co‐catalyzed synthesis of nine series of fused azaheterocycles with structural diversity starting from the same synthons as readily available propargylic hydroperoxides and aromatic amines has been achieved. The overall tandem process consists in a gold‐catalyzed hydroperoxide rearrangement/Michaelreaction followed by a final acid‐catalyzed cyclization.
Benzoyl Peroxide Promoted Radical<i>ortho</i>-Alkylation of Nitrogen Heteroaromatics with Simple Alkanes and Alcohols
作者:Lei Fang、Liangshun Chen、Jianjun Yu、Limin Wang
DOI:10.1002/ejoc.201403479
日期:2015.3
A catalytic amount of benzoylperoxide (BPO)-initiated cross-dehydrogenative coupling reaction of N-iminopyridine ylides with simplealkanes and alcohols leads to the corresponding 2-alkylpyridines with high regioselectivity in moderate to good yields without an additional reduction step to remove the activated group.
A Cu-mediated preparation of 2-substitiuted pyrazolo[1,5-a]pyridines from N-benzoylpyridinium imides and terminal alkynes is described using stoichiometric Cu(OAc)2 as both the mediator and the oxidant. Extensive DFT calculations suggest a Cu(III) intermediate via disproportionation of Cu(II).
描述了使用化学计量的Cu(OAc)2作为介体和氧化剂,由N-苯甲酰基吡啶鎓酰亚胺和末端炔烃组成的Cu介导的2取代吡唑并[1,5- a ]吡啶的制备方法。广泛的DFT计算表明,通过Cu(II)歧化可以生成Cu(III)中间体。