Arylation of Aldehydes To Directly Form Ketones via Tandem Nickel Catalysis
作者:Chuanhu Lei、Daoyong Zhu、Vicente III Tiu Tangcueco、Jianrong Steve Zhou
DOI:10.1021/acs.orglett.9b01782
日期:2019.8.2
both aliphatic and aromatic aldehydes proceeds with air-stable (hetero)arylboronic acids, with an exceptionally wide substrate scope. The neutral condition tolerates acidic hydrogen and sensitive polar groups and also preserves α-stereocenters of some chiral aldehydes. Interestingly, this nickel(0) catalysis does not follow common 1,2-insertion of arylmetal species to aldehydes and β-hydrogen elimination
Anionic polymerisation of phosphaalkenes bearing polyaromatic chromophores: phosphine polymers showing “turn-on” emission selectively with peroxide
作者:Benjamin W. Rawe、Cindy P. Chun、Derek P. Gates
DOI:10.1039/c4sc02133a
日期:——
respectively) to afford poly(methylenephosphine)s (PMPs: 2a: Mn = 15 100 Da, PDI = 1.14; 2b: Mn = 17 500 Da; PDI = 1.39). Detailed NMR spectroscopic analysis of polymer 2a revealed that its microstructure is primarily composed of [P(CHPhNaph)–(4,6-Me2C6H2)–2-CH2]n units rather than the expected [P(Mes)–CPh2]n. Functional polymer 2a was oxidised to the phosphine oxide 2a·O or phosphine sulfide 2a·S, and coordinated
Iron-catalyzed tandem carbon–carbon/carbon–oxygen bond formation/aromatization of 2′-alkynyl-biphenyl-2-carbinols: a new approach to the synthesis of substituted phenanthrenes
作者:Krishnendu Bera、Soumen Sarkar、Umasish Jana
DOI:10.1016/j.tetlet.2014.11.073
日期:2015.1
An iron-catalyzed efficientsynthesis of substituted phenanthrenes through tandem intramolecular C–C/C–O bond formations/aromatization of 2′-alkynyl-biphenyl-2-carbinols is reported. This method provides a novel, highlyefficient, and straightforward route to 9,10-substituted phenanthrene in good to excellent yields. The present strategy involves tandem Fe(OTf)3-catalyzed generation of benzylic carbocation
Synthesis of Substituted Phenanthrene by Iron(III)-Catalyzed Intramolecular Alkyne–Carbonyl Metathesis
作者:Krishnendu Bera、Soumen Sarkar、Swapnadeep Jalal、Umasish Jana
DOI:10.1021/jo301371n
日期:2012.10.5
An efficient synthesis of functionalized phenanthrenes has been developed for the first time involving an iron(III)-catalyzed intramolecular coupling of 2′-alkynyl-biphenyl-2-carbaldehydes. A broad range of functionalized phenanthrene derivatives could be obtained in the present method in moderate to good yields with high chemo- and regioselectivity. This transformation can also be applied to the synthesis
Charge delocalization from cationic substituents into phenanthrene: variation in response among regioisomeric carbocations and carboxonium ions
作者:Kenneth K. Laali、Sandro Hollenstein
DOI:10.1039/a707423i
日期:——
In an effort to assess charge delocalization and stabilities, a series of regioisomeric PAH–C+R2 carbocations (PAH = phenanthrene; R = Me, Ph) were generated from their alcohols by ionization with FSO3H/SO2ClF. Model carboxonium ions were also generated by O-protonation of the isomeric acetyl- and benzoyl-phenanthrenes with FSO3H/SO2ClF. The delocalization paths and the arenium ion character in the resulting carbocations and carboxonium ions are evaluated via low temperature NMR studies; conformational aspects in the carboxonium ions are also addressed. The resulting cations may serve as models for epoxide ring opening in biologically active dihydro diols of several classes of PAHs for which the diol epoxide activation path is believed to be significant in cancer induction.