Benzotriazole-Mediated [2,3]-Wittig Rearrangement. General and Stereocontrolled Syntheses of Homoallyl Alcohols and β,γ-Unsaturated Ketones
作者:Alan R. Katritzky、Hong Wu、Linghong Xie
DOI:10.1021/jo960019d
日期:1996.1.1
give secondary and tertiary homoallyl alcohols (16 and 21), respectively, exclusively in the E configuration in excellent yields. This is achieved by deprotonation followed by [2,3]-Wittig rearrangement, departure of the benzotriazolyl group, and then nucleophilic addition to the resulting carbonyl compound. Following a similar protocol, primary E-homoallyl alcohols 18 are prepared in good yield by the
作者:Martyn R. Ashcroft、Adrian Bury、Christopher J. Cooksey、Alwyn G. Davies、B.Dass Gupta、Michael D. Johnson、Helen Morris
DOI:10.1016/s0022-328x(00)93390-4
日期:1980.8
a chain mechanism in which a key step is a novelprocess in which homolytic attack of a trichloromethyl or 4-toluenesulphonyl radical at the δ-carbon of the butenyl ligand leads to synchronous or subsequent attack of the incipient γ-carbon radical on the α-carbon, causing cyclisation and displacement of cobaloxime(II). The other propagation step involves the reaction of the cobaloxime(II) with the
Iridium-Catalyzed Coupling Reaction of Primary Alcohols with 2-Alkynes Leading to Hydroacylation Products
作者:Shintaro Hatanaka、Yasushi Obora、Yasutaka Ishii
DOI:10.1002/chem.200902646
日期:2010.2.8
A novel iridium‐catalyzed intermolecularcoupling reaction of primary alcohols or aldehydes with 2‐alkynes was successfully achieved with high regioselectivity to give hydroacylation products such as α,β‐unsaturatedketones in good yields. The mechanistic investigation of the reaction strongly indicated that the coupling proceeds through the initial formation of homoallylic alcohols followed by dehydrogenation
STEREOSELECTIVE ACYCLIC SYNTHESIS VIA ALLYLMETALS: STRUCTURAL DEPENDENCE IN A LEWIS-ACID CATALYZED ADDITION OF ALLYLTINS TO ALDEHYDES
作者:Masato Koreeda、Yoshio Tanaka
DOI:10.1246/cl.1982.1299
日期:1982.8.5
Lewis-acid catalyzed reaction of allyltins with aldehydes at −78 °C provide homoallyl alcohols with high stereoselectivity; 2-alkenyltins in general provide erythro adducts preferentially with an erythro/threo ratio greater than 12/1, whereas only threo adducts can be obtained from E-cinnamyltins.
路易斯酸催化烯丙基锡与醛在 -78 °C 下的反应提供具有高立体选择性的高烯丙醇;2-烯基锡通常优先提供赤/苏比大于12/1的赤加合物,而从E-肉桂锡只能获得苏加加合物。
Versatile Homoallylic Boronates by Chemo‐, S
<sub>N</sub>
2′‐, Diastereo‐ and Enantioselective Catalytic Sequence of Cu−H Addition to Vinyl‐B(pin)/Allylic Substitution
作者:Jaehee Lee、Sebastian Torker、Amir H. Hoveyda
DOI:10.1002/anie.201611444
日期:2017.1.16
combines a silyl hydride, vinyl‐B(pin) (pin=pinacolato) and (E)‐1,2‐disubstituted allylic phosphates is introduced. Reactions, best promoted by a Cu‐based complex with a chiral sulfonate‐containing N‐heterocyclic carbene, are broadly applicable. Aryl‐, heteroaryl‐, alkenyl‐, alkynyl‐ and alkyl‐substituted allylic phosphates may thus be converted to the corresponding homoallylic boronates and then alcohols
引入了一种高度化学、非对映和对映选择性催化方法,可有效地将氢化硅烷、乙烯基-B(pin)(pin=频那醇)和(E)-1,2-二取代烯丙磷酸酯结合起来。铜基络合物与含手性磺酸盐的 N-杂环卡宾最能促进反应,具有广泛的适用性。因此,芳基、杂芳基、烯基、炔基和烷基取代的烯丙基磷酸酯可以转化为相应的高烯丙基硼酸酯,然后转化为醇(CB键氧化后),产率达 46-91%,最高可达 >98% S N 2':S N 2 比率、96:4非对映体比率和98:2对映体比率。借助 DFT 计算,提供了 NHC−Cu 催化剂独特有效的原因(相对于相应的膦系统)以及立体选择性不同趋势的基础。