Copper-Catalyzed Direct Ortho-Alkylation of <i>N</i>-Iminopyridinium Ylides with <i>N</i>-Tosylhydrazones
作者:Qing Xiao、Lin Ling、Fei Ye、Renchang Tan、Leiming Tian、Yan Zhang、Yuxue Li、Jianbo Wang
DOI:10.1021/jo4002883
日期:2013.4.19
Copper-catalyzedcross-coupling of N-tosylhydrazones with N-iminopyridinium ylides leads to the direct C–H alkylation. This direct C–H bond alkylation transformation uses inexpensive CuI as the catalyst without any ligand. The reaction is operationally simple and conducted under mild conditions, giving the corresponding alkylated pyridines in moderate to good yields. DFT calculation provides insights
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
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.
Highly regioselective synthesis of 2,4,5-(hetero)aryl substituted oxazoles by intermolecular [3+2]-cycloaddition of unsymmetrical internal alkynes
作者:Elli Chatzopoulou、Paul W. Davies
DOI:10.1039/c3cc45410j
日期:——
A robust N-nucleophilic 1,3-N,O-dipole equivalent reacts with unsymmetrical internal alkynes under gold catalysis. Conjugation from a remote nitrogen lone pair enables and controls this convergent and highly regioselective process.
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。