Allenyl Ketones as Versatile Michael Acceptors for the Addition of Chelated Enolates
作者:Uli Kazmaier、Simon Lucas
DOI:10.1055/s-2005-923591
日期:——
Chelated amino acid ester enolates undergo clean 1,4-addition towards allenyl ketones 9, giving rise to unsaturated δ-keto amino acid esters 12 at low temperature. If the reaction is allowed to warm to room temperature, the enolate intermediates A undergo cyclization towards the corresponding α-pyrones 13.
Zinc-Promoted Barbier-Type Reaction of Propargyl Bromide with Aldehydes in Aqueous Media
作者:Issa Yavari、Farhad Riazi-Kermani
DOI:10.1080/00397919508011422
日期:1995.10
Abstract In the prese of metallic zinc, propargylbromide is found to react with aldehydes at room temperature in tetrahydrofurane-saturated aqueous ammonium chloride (5:2) to afford the corresponding homopropargylic alcohols in moderate to high yields together with small amounts of α-allenic alchohols.
Synthesis of α-Borylmethyl-(<i>E</i>)-allylborons via Cu-Catalyzed Diboration of 1-Substituted Allenols and Their Application in Stereoselective Aldehyde Allylation
作者:Yeonjoo Lee、Hwiwoong Lee、Yurim Lee、Soohong Cho、Juhyung Lee、Joongoo Kang、Byunghyuck Jung、Yunmi Lee
DOI:10.1021/acscatal.2c06061
日期:2023.2.17
α-borylmethyl-(E)-allylborons was demonstrated by the enantio- and (Z)-selective allylation of aldehydes via Brønsted acid catalysis. Furthermore, (E)-allyl and (E)-homoallyl diols with excellent diastereoselectivity were generated by the Lewisacid catalyzed diastereo- and (E)-selective allyl transfer of (E)-allyldiborons to aldehydes. Using this strategy, the key intermediate in the construction of the C7–C12 fragment
在烯丙基和高烯丙基位置各有一个硼原子的 1,2-二硼具有很大的实用性,尤其是作为双烯丙基化试剂。然而,迄今为止只有少数合成方法被报道,并且底物范围有限。在此,我们开发了 Cu 催化的区域选择性和立体选择性合成 α-硼甲基-( E )-烯丙基硼,从易于获得的 1-取代丙二烯醇和双(频哪醇)二硼。重要的是,这种方法可以高效和区域选择性地形成具有不同取代基的双烯丙基化二硼,否则合成起来会很麻烦,并且可以在克规模上成功进行。α-硼甲基-( E )-烯丙基硼的合成应用通过对映-和( Z)-通过 Brønsted 酸催化对醛进行选择性烯丙基化。此外,通过路易斯酸催化的 ( E )-烯丙基二硼的非对映和 (E)- 选择性烯丙基转移至醛,生成了具有优异非对映选择性的 (E)-烯丙基和( E ) -高烯丙基二醇。使用该策略,还合成了构建(−)-discodermolide 的C 7 –C 12片段的关键中间体。
Cu-Catalyzed Synthesis of 2-Silyl-1,3-butadienes from Allenols and Applications to One-Pot Synthesis of Tetrasubstituted Arylsilanes
chemo- and stereoselective method for the synthesis of (E)-2-silyl-1,3-butadienes from a broad range of allenols using mild Si–B reagents is reported in this study. Our protocol required a short reaction time at ambient temperature to produce the desired dienes in high yields. Synthetic applications are highlighted by the one-potsynthesis of tetrasubstituted arylsilanes from allenols as well as the
本研究报道了一种铜催化化学和立体选择性方法,使用温和的 Si-B 试剂从多种联烯醇合成 ( E )-2-甲硅烷基-1,3-丁二烯。我们的方案需要在环境温度下进行短反应时间才能以高产率产生所需的二烯。从联烯醇一锅合成四取代芳基硅烷以及 C-Si 键的进一步功能化突出了合成应用。
Syntheses and Synthetic Applications of Stannylated Allylic Alcohols
作者:Uli Kazmaier、Simon Lucas、Manuela Klein
DOI:10.1021/jo052611l
日期:2006.3.1
Allenyl carbinols undergo regioselective hydrostannation in the presence of MoBl(3), a catalyst originally developed for the hydrostannation of alkynes, giving rise to allyl stannanes, These allyl stannanes can easily be converted into useful synthetic building blocks such as allyl iodides or vinyl epoxides.