“Me3Al-TMSOSO2CF3” A new reagent for conversion of carbonyl to geminal dimethyl functionality: Regiospecific synthesis of alkylated A ring of arotinoids
A new and efficient approach for the synthesis of oxygen and nitrogen heterocycles by organoselenium catalysis has been developed. The exo-cyclization proceeded smoothly under mild conditions with good functional group tolerance and excellent regioselectivity. Mechanistic studies revealed that 1-fluoropyridinium triflate is key for oxidative cyclization.
Intermolecular Addition Reaction to Alkenes of Acylmolybdenum Complexes Generated by Oxidative Addition of Aryl or Alkenyl Halides with Molybdenum(0) Carbonyl Complexes
Acylmolybdenum species, generated by oxidativeaddition of aryl or alkenyl halides with molybdenum(0) carbonylcomplex followed by carbon monoxide insertion, added to various kinds of alkenes intermolecularly to give simple addition products in good yields without formation of carbonylative Heck-type products.
Abstract A highly efficient intermolecular mutual addition of aromaticaldehydes with ethyl acrylate was developed by using tris(4-methoxylphenyl)phosphine as the catalyst. The reaction corresponds to the construction of 1,4-dicarbonyl compound and allylic alcohol fragments, which also provides a new way to form C-C bond. GRAPHICAL ABSTRACT
Photocatalytic 1,2-oxo-alkylation reaction of styrenes with diazoacetates
作者:Fang Li、Siqi Zhu、Rene M. Koenigs
DOI:10.1039/d2cc02414d
日期:——
reactivity of diazoalkanes can be suppressed and a 1,2 oxo-alkylation reaction can be achieved (32 examples, up to 94% yield) without the formation of cyclopropane by-products via the formation of radical intermediates from ethyldiazoacetate.
Catalyst for polymerization of olefin and process for the preparation of olefin polymer
申请人:SHOWA DENKO KABUSHIKI KAISHA
公开号:EP0640624A1
公开(公告)日:1995-03-01
A catalyst for producing a polyolefin having a high melting point and a high stereoregularity, which comprises: (A) a solid catalyst component containing titanium, magnesium and halogen, (B) an organic aluminum compound, and (C) an organic silicon compound represented by formula (1):
wherein R¹, R² and R³ each represents a C₁₋₃ hydrocarbon group.