Simple and efficient nickel-catalyzed cross-coupling reaction of alkynylalanes with benzylic and aryl bromides
作者:Deepak B. Biradar、Han-Mou Gau
DOI:10.1039/c1cc14206b
日期:——
efficient and simple coupling reactions of benzylic and arylbromides with aluminium acetylide catalyzed by NiCl(2)(PPh(3))(2) are reported. The coupling reactions proceed at room temperature employing 4 mol% catalyst, affording coupling products in excellent yields of up to 95% in short reaction times. The system worked efficiently with aryl and heterocyclic bromides as well.
Rhodium(III)/Copper(II)-Promoted<i>trans</i>-Selective Heteroaryl Acyloxylation of Alkynes: Stereodefined Access to<i>trans</i>-Enol Esters
作者:Manh V. Pham、Nicolai Cramer
DOI:10.1002/anie.201409450
日期:2014.12.22
synthesis by O‐selective enolate acylation often hampers control of the E/Z selectivity with highly substituted substrates. A rhodium(III)/copper(II)‐mediated process is reported to provide tetrasubstituted enol esters in a trans‐selective fashion. Overall, the reaction consists of a heteroaryl acyloxylation of alkynes. The process is initiated by a rhodium(III)‐catalyzed C2‐selective activation of
highly efficient palladium-catalyzed Sonogashira coupling of benzylic ammonium salts with terminal alkynes is developed. This strategy provides a facile access to a series of internal alkyne derivatives in moderate to excellent yields via C-N bond cleavage and C(sp3)-C(sp) bondformation. The broad substrate scope and high functionalgroup tolerance make this reaction attractive for organic synthesis
Rotational correlation times and radii of dithiazol-2-yl and dithiazolidin-2-yl free radicals
作者:Shirley A. Fairhurst、Roger S. Pilkington、Leslie H. Sutcliffe
DOI:10.1039/f19837900439
日期:——
2-dithiazolidin-2-yl radicals have been shown to be useful model compounds for detailed e.s.r. studies of rotational reorientation in liquid and frozen media. Consequently they are also potentially useful spin probes and spin labels. The e.s.r. powder spectra have been analysed and the resulting g and A tensors were used to calculate rotational diffusion correslation times, rotational energetics of activation
Cu-Catalyzed electrophilic amination of internal alkynes via hydroalumination
作者:Hongju Yoon、Yuna Kim、Yunmi Lee
DOI:10.1039/c6ob02606k
日期:——
efficient method for the synthesis of 1,2-diaryl-substituted enamines through the Cu-catalyzed electrophilicamination reaction of O-benzoyl hydroxylamines with vinylaluminum reagents generated in situ from the Ni-catalyzed hydroalumination of readily accessible internal aryl acetylenes is described. The amination is catalyzed by 1 mol% CuCl without any additive at ambient temperature to afford new versatile