A Facile and Modular Synthesis of Phosphinooxazoline Ligands
作者:Kousuke Tani、Douglas C. Behenna、Ryan M. McFadden、Brian M. Stoltz
DOI:10.1021/ol070884s
日期:2007.6.1
iodide catalyzed phosphine/aryl halide coupling procedure of Buchwald et al. provides modular, robust, and scaleable access to phosphinooxazoline (PHOX) ligands. The advantages of this method are highlighted by the convenient synthesis of PHOX ligands with varied steric and electronic properties, which would be challenging to synthesize by other protocols.
Palladium-Catalyzed Decarboxylative Asymmetric Allylic Alkylation of Enol Carbonates
作者:Barry M. Trost、Jiayi Xu、Thomas Schmidt
DOI:10.1021/ja9053948
日期:2009.12.30
extended to a variety of cyclic or acyclic disubstituted allyl groups. Our mechanistic studies reveal that, similar to the direct allylation of lithium enolates, the DAAA reaction proceeds through an "outer sphere" S(N)2type of attack on the pi-allylpalladium complex by the enolate. An important difference between the DAAA reaction and the direct allylation of lithium enolates is that in the DAAA reaction
Development of (Trimethylsilyl)ethyl Ester Protected Enolates and Applications in Palladium-Catalyzed Enantioselective Allylic Alkylation: Intermolecular Cross-Coupling of Functionalized Electrophiles
作者:Corey M. Reeves、Douglas C. Behenna、Brian M. Stoltz
DOI:10.1021/ol500355z
日期:2014.5.2
compounds in palladium-catalyzedasymmetricallylicalkylation is explored, yielding a variety of α-quaternary six- and seven-membered ketones and lactams. Independent coupling partner synthesis engenders enhanced allyl substrate scope relative to traditional β-ketoester substrates; highly functionalized α-quaternary ketones generated by the union of (trimethylsilyl)ethyl β-ketoesters and sensitive
Unusual Allylpalladium Carboxylate Complexes: Identification of the Resting State of Catalytic Enantioselective Decarboxylative Allylic Alkylation Reactions of Ketones
作者:Nathaniel H. Sherden、Douglas C. Behenna、Scott C. Virgil、Brian M. Stoltz
DOI:10.1002/anie.200902575
日期:2009.9.1
Palladium pop rocks: Hold on to your CO2! Enantioselective palladium‐catalyzed decarboxylative alkylation of ketone enolates proceeds via η1‐σ‐allyl palladium–carboxylate complexes, such as 1 (Pd yellow, O red, N blue, P purple), by slow loss of CO2. Reminiscent of pop rock candy, impure samples of 1 expel a gas (presumably CO2) in the solid state and effervesce in solution.
钯金流行摇滚:坚持住你的 CO 2!酮烯醇化物的对映选择性钯催化脱羧烷基化通过 η 1 -σ-烯丙基钯-羧酸盐络合物进行,例如1(Pd 黄色、O 红色、N 蓝色、P 紫色),通过缓慢损失 CO 2。让人想起流行的冰糖,1 的不纯样品排出固态气体(可能是 CO 2)并在溶液中泡腾。
The Inner-Sphere Process in the Enantioselective Tsuji Allylation Reaction with (<i>S</i>)-<i>t</i>-Bu-phosphinooxazoline Ligands
作者:John A. Keith、Douglas C. Behenna、Justin T. Mohr、Sandy Ma、Smaranda C. Marinescu、Jonas Oxgaard、Brian M. Stoltz、William A. Goddard
DOI:10.1021/ja070516j
日期:2007.10.1
We propose an inner-sphere mechanism explaining the unique performance of the Tsuji asymmetrical allylation reaction using hard prochiral enolate nucleophiles and non-prochiral allyl groups. Using first principles quantum mechanics (B3LYP density functional theory), we find that the pathway for this reaction involves nucleophilic attack followed by interconversion from a five-coordinate Pd complex