Palladium-Catalyzed Alkylation of 1,4-Dienes by CH Activation
作者:Barry M. Trost、Max M. Hansmann、David A. Thaisrivongs
DOI:10.1002/anie.201200601
日期:2012.5.14
Activated: the title reaction proceeds with a broad range of nucleophiles and variously substituted 1,4-dienes under mild conditions, and provides direct access to the corresponding 1,3-diene-containing products with high regio- and stereocontrol (see scheme; 2,6-DMBQ=2,6-dimethylbenzoquinone, EWG=electron-withdrawing group). This is the first catalytic allylic C-H alkylation that proceeds in the absence of sulfoxide ligands.
Pentadienylzirconium compounds: easily accessible new reagents for selective pentadienylation reactions
2,4-Pentadienylzirconium complexes are generated from 2,4- or 2,2'-pentadienyl ethers in turn. These compounds react in situ with aldehydes and ketones in a totally gamma -regioselective manner and with predominant anti stereoselectivity to produce bis(homoallylic) alcohols in good yields. Iodocyclization of one of these alcohols represents regio- and stereocontrolled short entry to functionalized tetrahydrofurans. (C) 2001 Elsevier Science Ltd. All rights reserved.
Palladium-Catalyzed Homocoupling Reactions between Two Csp<sup>3</sup>−Csp<sup>3</sup> Centers
作者:Aiwen Lei、Xumu Zhang
DOI:10.1021/ol0258536
日期:2002.7.1
see text] A novel palladium-catalyzed coupling reaction between two Csp(3)-Csp(3) centers has been investigated. This protocol is initiated by the oxidative addition of an alpha-halo carbonyl compound to a palladium(0) species, followed by the double transmetalation. The key dialkyl palladium intermediate undergoes reductive elimination to form the desired coupling product.
Regio‐ and Stereoselective Homologation of 1,2‐Bis(Boronic Esters): Stereocontrolled Synthesis of 1,3‐Diols and Sch 725674
作者:Alexander Fawcett、Dominik Nitsch、Muhammad Ali、Joseph M. Bateman、Eddie L. Myers、Varinder K. Aggarwal
DOI:10.1002/anie.201608406
日期:2016.11.14
1,2-Bis(boronic esters), derived from the enantioselective diboration of terminal alkenes, can be selectively homologated at the primary boronic ester by using enantioenriched primary/secondary lithiated carbamates or benzoates to give 1,3-bis(boronic esters), which can be subsequently oxidized to the corresponding secondary-secondary and secondary-tertiary 1,3-diols with full stereocontrol. The transformation