Substitution of vinylic iodides by various copper(I) and copper(II) derivatives
作者:A. Commercon、J. Normant、J. Villieras
DOI:10.1016/s0022-328x(00)94014-2
日期:1975.7
Vinyl iodides have been treated with various copper(I) derivatives (aryl- and alkyl-copper derivatives, copper(I) chloride, cyanide, bromide, thiolate) and found to undergo substitution at carbon with retention of configuration. Copper(II) carboxylates give much better yields of enol esters than the corresponding copper(I) salts. A four centre mechanism accounts best for the results.
Stereocontrolled Synthesis of Carbon Chains Bearing Contiguous Methyl Groups by Iterative Boronic Ester Homologations: Application to the Total Synthesis of (+)-Faranal
作者:Guillaume Dutheuil、Matthew P. Webster、Paul A. Worthington、Varinder K. Aggarwal
DOI:10.1002/anie.200901194
日期:——
the chain: A quadruple homologation of a boronic ester converts a simple vinyl iodide into a complex precursor to faranal with very high levels of diastereo‐ and enantiocontrol. This enables the synthesis of (+)‐faranal to be completed in just six steps and 18 % overall yield from propyne.
Iodoalkenes give symmetrical couplings to dienes with complete retention of configuration when treated with organolithium reagents in the presence of catalytic amounts of manganese(II) salts. A catalytic cycle is proposed through lithium manganate derivatives and manganese(IV) derivatives.
Diastereo- and Enantioselective Synthesis of Homoallylic Amines Bearing Quaternary Carbon Centers
作者:Jacob C. Green、Joseph M. Zanghi、Simon J. Meek
DOI:10.1021/jacs.9b11529
日期:2020.1.29
A Cu-catalyzed method for the efficient enantio- and diastereoselective synthesis of chiral homoallylic amines bearing a quaternary carbon and an alkenylboron is disclosed. Transformations are promoted by a readily prepared (phosphoramidite)-Cu complex, and involve bench-stable γ,γ,-disubstituted allyldiborons and benzyl imines; products are obtained in up to 82% yield, >20:1 dr, and >99:1 er. Reactions