Preparation of new classes of aliphatic, allylic, and benzylic zinc and copper reagents by the insertion of zinc dust into organic halides, phosphates, and sulfonates
摘要:
The insertion of zinc dust into primary alkyl chlorides, bromides, phosphates, and sulfonates in a polar solvent (DMPU, DMA) and in the presence of a catalytic amount of LiI (0.2 equiv) provides new organozinc reagents of the type RZnX (X = Cl, Br, OSO2R, OP(O)(OR)2) in excellent yields. After the transmetalation to the corresponding copper reagent RCu(CN)ZnX using CuCN.2LiCl, the addition of electrophiles, such as Michael acceptors, affords the desired adducts. Similarly, various new allylic and benzylic zinc reagents were prepared without the formation of any Wurtz-coupling side product and reacted with various electrophiles.
Regio-controlled Prenylation and Geranylation of 3-Furylmethylmagnesium Bromide. Selective Syntheses of 3-Substituted Furanoid and 2-Substituted 3-Methylfuranoid Terpenes
作者:Shuki Araki、Yasuo Butsugan
DOI:10.1246/bcsj.56.1446
日期:1983.5
main products. When the reactions were carried out in the presence of a catalytic amount of copper(I) iodide, normal coupling occurred and 3-substituted furans, perillene and dendrolasin, were formed in good yields. The related naturally occurring 3-substitutedthiophene, 3-(4-methyl-3-pentenyl)thiophene, was also synthesized from 3-thienylmethylmagnesium bromide and prenyl diethy phosphate.
Iridium Complex-Catalyzed Allylic Alkylation of Allylic Esters and Allylic Alcohols: Unique Regio- and Stereoselectivity
作者:Ryo Takeuchi、Mikihiro Kashio
DOI:10.1021/ja981560p
日期:1998.9.1
An iridiumcomplex was found to be an efficient catalyst for allylicalkylation of allylic esters with a stabilized carbonnucleophile. Highly regioselective alkylation at the substitutedallylic t...
Copper-Catalyzed S<sub>N</sub>2′-Selective Allylic Substitution Reaction of <i>gem</i>-Diborylalkanes
作者:Zhen-Qi Zhang、Ben Zhang、Xi Lu、Jing-Hui Liu、Xiao-Yu Lu、Bin Xiao、Yao Fu
DOI:10.1021/acs.orglett.5b03692
日期:2016.3.4
A Cu/(NHC)-catalyzed SN2′-selective substitution reaction of allylic electrophiles with gem-diborylalkanes is reported. Different substituted gem-diborylalkanes and allylic electrophiles can be employed in this reaction, and various synthetic valuable functional groups can be tolerated. The asymmetric version of this reaction was initially researched with chiral N-heterocyclic carbene (NHC) ligands
报道了Cu /(NHC)催化的烯丙基亲电试剂与宝石-二硼烷基烷烃的S N 2'-选择性取代反应。在该反应中可以使用不同的取代的宝石-二硼烷基烷烃和烯丙基亲电子试剂,并且可以容许各种合成的有价值的官能团。最初使用手性N-杂环卡宾(NHC)配体研究了该反应的不对称形式。
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.