1-Methoxy-2-alkanones are prepared from ate-complexes formed from 1,2-dimethoxyethenyllithium and trialkylboranes by the reaction with BF3:Et2O, followed by basic hydrogen peroxide oxidation.
Photoinduced Carboborative Ring Contraction Enables Regio- and Stereoselective Synthesis of Multiply Substituted Five-Membered Carbocycles and Heterocycles
作者:Shengfei Jin、Vu T. Nguyen、Hang T. Dang、Dat P. Nguyen、Hadi D. Arman、Oleg V. Larionov
DOI:10.1021/jacs.7b07128
日期:2017.8.23
herein a photoinduced carboborative ringcontraction of monounsaturated six-membered carbocycles and heterocycles. The reaction produces substituted five-membered ring systems stereoselectively and on preparative scales. The products feature multiple stereocenters, including contiguous quaternary carbons. We show that the reaction can serve as a synthetic platform for ring system alteration of natural products
Deoxygenative α-alkylation and α-arylation of 1,2-dicarbonyls
作者:Shengfei Jin、Hang T. Dang、Graham C. Haug、Viet D. Nguyen、Hadi D. Arman、Oleg V. Larionov
DOI:10.1039/d0sc03118f
日期:——
challenging but synthetically indispensable approach to α-branched carbonyl motifs that are widely represented among drugs, natural products, and synthetic intermediates. Here, we describe a simple approach to generation of boron enolates in the absence of strong bases that allows for introduction of both α-alkyl and α-aryl groups in a reaction of readily accessible 1,2-dicarbonyls and organoboranes. Obviation
An Atom-Economic and Selective Ruthenium-Catalyzed Redox Isomerization of Propargylic Alcohols. An Efficient Strategy for the Synthesis of Leukotrienes
作者:Barry M. Trost、Robert C. Livingston
DOI:10.1021/ja804105m
日期:2008.9.10
secondary propargylicalcohols in good yields to provide trans enals and enones exclusively. Readily available indenylbis(triphenylphosphine)ruthenium chloride, in the presence of indium triflate and camphorsulfonic acid, gives the best turnover numbers and reactivity with the broadest range of substrates. Deuterium labeling experiments suggest that the process occurs through propargylic hydride migration
platinum electrodes in the presence of α,β-unsaturated esters in an acetonitrile solution containing tetraalkylammonium halide as a supporting electrolyte, produces the corresponding alkylated carboxylic acid esters in good yields.