Synthesis of Short-Chain Alkenyl Ethers from Primary and Bio-sourced Alcohols via the Nickel-Catalyzed Hydroalkoxylation Reaction of Butadiene and Derivatives
Hydroalkoxylation of butadiene has been performed in the presence of nickel precatalysts associated with chelating diphosphine ligands. High butadiene conversions and selectivities forming alkyl butenyl ethers were obtained with low catalyst loading. Reactions were performed with a wide scope of primary alcohols including benzylic alcohol derivatives and bio‐sourced alcohols. In the same way, the scope
Ketones bearing a hetero-atom at α-position were methylenated selectively by CH2(ZnI)2 to give allylic alcohols; a nucleophilic attack of the zinc species was accelerated with a coordination of a hetero-atom at α-position.
Metal-Catalyzed Silylene Insertions of Allylic Ethers: Stereoselective Formation of Chiral Allylic Silanes
作者:Laura E. Bourque、Pamela A. Cleary、K. A. Woerpel
DOI:10.1021/ja073758s
日期:2007.10.1
Silylene insertion into allylicethers occurs suprafacially to provide enantioenriched allylic silanes and disilanes. Silylene insertion to a variety of protected allylic alcohols utilizing silver- and copper-mediated conditions proved to be a general method for allylic silane formation. Allylic disilanes reacted similarly to allylic silanes, undergoing both annulation and allylation reactions.
Silylene oxonium ylides: di-tert-butylsilylene insertion into C–O bonds
作者:Laura E. Bourque、Pamela A. Haile、Janice M.N. Loy、K.A. Woerpel
DOI:10.1016/j.tet.2009.04.016
日期:2009.7
Allylic ethers undergo insertions of silylenes into C-O bonds to form allylic silanes. Silylene insertion into C-O acetal bonds was also observed. Formation of silylene ylide intermediates led to [ 1,2]-Stevens rearrangement products as well as [2,3]-sigmatropic products depending upon the steric environment of the starting allylic ether. (C) 2009 Elsevier Ltd. All rights reserved.