Ligandless Iron-Catalyzed Desulfinylative CâC Allylation Reactions using Grignard Reagents and Alk-2-enesulfonyl Chlorides
作者:Chandra M. R. Volla、Dean MarkovicÌ、Srinivas Reddy Dubbaka、Pierre Vogel
DOI:10.1002/ejoc.200900927
日期:2009.12
regioselectivity of these allylations was studied by using sulfonyl chlorides 3 and 4 with aryl Grignard reagents. The scope of these allylations was further extended by the coupling of ester-substituted alk-2-enesulfonylchloride 10 with aromatic Grignard reagents. Symmetrical products were synthesized by double C-C allylation with the use of 2-methylidenepropane-1,3-disulfonyl chloride (12). ((C) Wiley-VCH
Nickel and palladiumcomplexes with the 1,1′-bis(diphenylphosphino)ferrocene ligand effectively catalyze regioselective cross-coupling of allylic ethers such as 1- or 3-methyl-2-propenyl silyl ethers with aryl-Grignard reagents, where the nickel catalyst leads to carbon—carbonbondformation at the more substituted position while carbon–carbon bondformation occurs at the less substituted position
Palladium-catalyzed desulfinylative C–C allylation of Grignard reagents and enolates using allylsulfonyl chlorides and esters
作者:Chandra M. Rao Volla、Srinivas Reddy Dubbaka、Pierre Vogel
DOI:10.1016/j.tet.2008.11.007
日期:2009.1
(E)-but-2-enesulfonyl chlorides have been used as electrophilic partners in desulfinylative palladium-catalyzed C–C coupling with Grignardreagents and sodium salts of dimethyl malonate and methyl acetoacetate. Neopentyl alk-2-ene sulfonates can also be used as electrophilic partners in desulfinylative allylic arylations and allylic alkylations. The regioselectivity of the allylic arylation and alkylation depends
Hansen,H.-J. et al., Helvetica Chimica Acta, 1968, vol. 51, p. 828 - 867
作者:Hansen,H.-J. et al.
DOI:——
日期:——
γ-Selective Cross-Coupling of Allylic Silanolate Salts with Aromatic Bromides Using Trialkylphosphonium Tetrafluoroborate Salts Prepared Directly from Phosphine•Borane Adducts
作者:Scott E. Denmark、Nathan S. Werner
DOI:10.1021/ol2017998
日期:2011.9.2
γ-selective, palladium-catalyzedcross-coupling of sodium (Z)-2-butenyldiethylsilanolate with a variety of aromatic bromides is reported. The protocol provides high yields (73–94%) and site selectivity (γ/α, 25:1 → > 99:1) in the coupling of electron-rich, electron-poor, sterically hindered, and heteroaromatic bromides. The use of a configurationally homogeneous (Z)-silanolate, nontransferable ethyl groups
报道了γ 选择性、钯催化的 ( Z )-2-丁烯基二乙基硅烷醇钠与多种芳香族溴化物的交叉偶联。该协议在富电子、缺电子、空间位阻和杂芳族溴化物的耦合中提供了高产率 (73–94%) 和位点选择性 (γ/α, 25:1 → > 99:1)。使用由相应的空气稳定膦•硼烷加合物直接制备的构型均匀的 ( Z )-硅烷醇化物、不可转移的乙基和空间庞大的三烷基鏻四氟硼酸盐 ( t -BuCy 2 PH + BF 4 – ) 对方法的成功。