Catalytic α-Allylation of Enones with Alcohols <i>via</i>
[Gold(I)]-Mediated [3,3]-Sigmatropic Rearrangement of Propargylic Carboxylates
作者:Elisabetta Manoni、Mario Daka、Marco M. Mastandrea、Assunta De Nisi、Magda Monari、Marco Bandini
DOI:10.1002/adsc.201600113
日期:2016.4.28
The site‐selective α‐allylic alkylation of enones with alcohols via gold‐triggered formation of nucleophilic allenoates by means of [3,3]‐sigmatropic rearrangements of propargylic carboxylates is reported. A range of α‐alkylated enones is obtained in high yields in the presence of the gold complex [JohnPhosAu(ACN)]SbF6 (2 mol%) as the promoting agent. Examples of allylation/Friedel–Crafts alkylation
Controllable chemoselectivity in the coupling of bromoalkynes with alcohols under visible-light irradiation without additives: synthesis of propargyl alcohols and α-ketoesters
作者:Ke Ni、Ling-Guo Meng、Hongjie Ruan、Lei Wang
DOI:10.1039/c9cc04090k
日期:——
The chemoselectivity of visible-light-induced coupling reactions of bromoalkynes with alcohols can be controlled by simple changes to the reaction atmosphere.
Synthesis of highly substituted allylic alcohols by a regio- and stereo-defined CuCl-mediated carbometallation reaction of 3-aryl-substituted secondary propargylic alcohols with Grignard reagents
作者:Xiaobing Zhang、Zhan Lu、Chunling Fu、Shengming Ma
DOI:10.1039/b903769a
日期:——
A highly regio- and stereoselective CuCl-mediated carbometallation reaction of 3-aryl-substituted secondary propargylicalcohols with alkyl, aryl, vinyl or allyl Grignard reagents for the synthesis of fully-substituted allylic alcohols was developed. The R2group from the Grignard reagent was successfully introduced to the 2-position of the propargylicalcohols due to the chelation of metal atom with
We have achieved the nickel-catalyzed asymmetric propargylic amination of propargylic carbonates bearing an internal alkyne group. A wide variety of propargylic carbonates and N-methylaniline derivatives were tolerated under the reaction conditions, providing the corresponding chiral propargylic amines in up to 97% yield with up to 97% ee.
resolution of propargyloxy dicarbonyl compounds via asymmetric [2,3]-Wittigrearrangement was achieved by using a chiral N,N′-dioxide/NiII complex catalyst. Various chiral α-allenyl alcohols were obtained in high enantioselectivities under mild conditions. The utility of this method was readily demonstrated in the asymmetric synthesis of the chiral 2,5-dihydrofuran derivative.
通过使用不对称的[2,3] -Wittig重排,可以通过使用手性N,N'-二氧化物/ Ni II络合物催化剂实现炔丙氧基二羰基化合物的有效动力学拆分。在温和条件下以高对映选择性获得了各种手性α-烯丙醇。该方法的实用性很容易在手性2,5-二氢呋喃衍生物的不对称合成中得到证明。