Palladium-Catalyzed Asymmetric Allylic Alkylation of Ketone Enolates
作者:Barry M. Trost、Gretchen M. Schroeder
DOI:10.1002/chem.200400666
日期:2005.1
Palladium-catalyzed asymmetric allylic alkylation of nonstabilized ketone enolates to generate quaternary centers has been achieved in excellent yield and enantioselectivity. Optimized conditions consist of performing the reaction in the presence of two equivalents of LDA as base, one equivalent of trimethytin chloride as a Lewis acid, 1,2-dimethoxyethane as the solvent, and a catalytic amount of a
enantioselective allylic alkylation of terminal alkynes with primary allylic phosphates was developed by the use of a new chiral N-heterocyclic carbene ligand bearing a phenolic hydroxy group at the ortho position of one of the two N-aryl groups. This reaction occurred with excellent γ-branch regioselectivity and high enantioselectivity, forming a controlled stereogenic center at the allylic/propargylic
Nickel-Catalyzed C–H Coupling with Allyl Phosphates: A Site-Selective Synthetic Route to Linear Allylarenes
作者:Xuefeng Cong、Yuexuan Li、Yu Wei、Xiaoming Zeng
DOI:10.1021/ol501707z
日期:2014.8.1
reported that a nickel/phosphine catalyst allows the C–H allylation to occur effectively with the allyl site selectivity predominantly governed by steric effects. This reaction provides a facile and predictable route for the selective preparation of linear allylarenes from readily available benzamides and allyl phosphates.
A chromium ate-type reagent
‘Bu5CrLi2’ reacts with allylic and
propargylic phosphates to generate the corresponding allyl- and
propargylchromium (propargyl = prop-2-ynyl) reagents which further react
with a variety of electrophiles such as aldehydes, ketones, imines, and
isocyanates to afford the corresponding adducts in high yields.
Highly Regioselective Coupling Reactions of Allylic and Propargylic Alcohol Derivatives with γ,γ-Dialkoxyallylic Zirconium Species via Zr-to-Cu Transmetalation
作者:Azusa Sato、Hisanaka Ito、Takeo Taguchi
DOI:10.1021/jo0489216
日期:2005.1.1
In the presence of CuCN, reaction of γ,γ-dialkoxyallylic zirconium species 4, generated in situ by treating triethyl orthoacrylate with zirconocene−butene complex, with allylic and propargylic phosphates proceeded at the α-position of 4 in a highly SN2‘-selective manner to give the corresponding 5-alkenoates and 4,5-alkadienoates, respectively. In the present Cu(I)-mediated coupling reaction, the γ
在存在CuCN的情况下,通过用锆茂茂-丁烯配合物处理原丙烯酸三乙酯与烯丙基和炔丙基磷酸酯在高S N 2'中在4的α位进行原位生成的γ,γ-二烷氧基烯丙基锆物种4的反应。选择性地分别得到相应的5-链烯酸酯和4,5-链二烯酸酯。在当前的Cu(I)介导的偶联反应中,γ,γ-二烷氧基烯丙基锆物种4用作丙酸酯的合成有用的均烯酸酯阴离子当量。