Versatile C(sp<sup>2</sup>)−C(sp<sup>3</sup>) Ligand Couplings of Sulfoxides for the Enantioselective Synthesis of Diarylalkanes
作者:William M. Dean、Mindaugas Šiaučiulis、Thomas E. Storr、William Lewis、Robert A. Stockman
DOI:10.1002/anie.201602264
日期:2016.8.16
The reaction of chiral (hetero)aryl benzyl sulfoxides with Grignard reagents affords enantiomerically pure diarylalkanes in up to 98 % yield and greater than 99.5 % enantiomeric excess. This ligand coupling reaction is tolerant to multiple substitution patterns and provides access to diverse areas of chemical space in three operationally simple steps from commercially available reagents. This strategy
Nucleophilic<i>ortho</i>-Propargylation of Aryl Sulfoxides: An Interrupted Pummerer/Allenyl Thio-Claisen Rearrangement Sequence
作者:Andrew J. Eberhart、David J. Procter
DOI:10.1002/anie.201300223
日期:2013.4.2
A new direction: The nucleophilic ortho‐propargylation of aryl sulfoxides exploits intermolecular delivery of the nucleophile to sulfur followed by an intramolecular relay to carbon (see scheme). The simple, metal‐free procedure is general, regiospecific with regard to the propargyl nucleophile, and completely selective for products of ortho‐propargylation over allenylation.
Nickel-catalyzed Negishi-type cross-coupling of aryl methyl sulfoxides with arylzinc reagents has been developed. By consuming the catalyst-oxidizing methanesulfenate anion through oxidative homocoupling of the arylzinc reagent, smooth catalyst turnover could be executed. Arylzinc reagents prepared from arylmagnesium bromide, zinc bromide, and lithium bromide were optimal to afford the products in
Sulfoxide-Directed Metal-Free<i>ortho</i>-Propargylation of Aromatics and Heteroaromatics
作者:Andrew J. Eberhart、Harry J. Shrives、Estela Álvarez、Amandine Carrër、Yuntong Zhang、David J. Procter
DOI:10.1002/chem.201406424
日期:2015.5.11
exploits intermolecular delivery of a propargyl nucleophile to sulfur followed by an intramolecular relay to carbon. The operationally simple cross‐coupling procedure is general, regiospecific with regard to the propargyl nucleophile, and shows complete selectivity for products of ortho‐propargylation over allenylation. The use of secondary propargyl silanes allows metal‐free ortho‐coupling to form carbon–carbon