在本文中,我们描述了由双取代的烯酮和非手性醛形成带有两个立体中心的β-内酯的一般催化程序。发现BINAPHANE在催化由非手性醛(芳族和脂族)和两个非手性醛形成带有两个立构中心的β-内酯时,表现出优异的对映选择性(对于8个实例≥90%ee)和良好的非对映选择性(对于13个实例≥90:10)。烷基芳基烯酮或二烷基烯酮。在这些反应中观察到偏好形成反式非对映异构体。对于那些其中BINAPHANE失败作为催化剂的反应,三Ñ发现丁基丁基膦是一种有效的非手性亲核催化剂,在外消旋β-内酯的形成中具有良好的收率和非对映选择性。通过31 P NMR光谱监测反应并与在膦催化的乙烯酮均二聚反应中观察到的先前表征的中间体进行比较,获得了有关烯醇中间体参与反应机理的证据。
Tandem [2+2] cycloaddition-cycloreversion reactions in highly polar media: A convergent one-pot entry to substituted alkenes and dienes
作者:Iosune Arrastia、Fernando P. Cossío
DOI:10.1016/0040-4039(96)01562-6
日期:1996.9
Reaction at room temperature between acyl chlorides and aromatic or α,β-unsaturated aldehydes in the presence of a tertiary base and in 5M lithium perchlorate-diethyl ether (5M LPDE) as solvent yields substitutedalkenes in satisfactory yields. The reaction is formally conceived as a [2+2] cycloaddition between the aldehyde and the in situ formed ketene, followed by thermal decarboxylation of the intermediate
Solvate Ionic Liquids as Reaction Media for Electrocyclic Transformations
作者:Daniel J. Eyckens、Megan E. Champion、Bronwyn L. Fox、Prusothman Yoganantharajah、Yann Gibert、Tom Welton、Luke C. Henderson
DOI:10.1002/ejoc.201501614
日期:2016.2
Solvate ionicliquids (SILs) consisting of lithium bis(trifluoromethylsulfonyl)imide dissolved in tri- or tetraglyme have recently emerged as a novel class of ionicliquids. Herein, the first use of solvate ionicliquids as a replacement for molecular solvents in electrocyclization reactions is reported. The SILs promoted both Diels–Alder and [2+2] cycloaddition reactions, compared to an appropriate
Phosphine-Catalyzed Asymmetric Synthesis of β-Lactones from Disubstituted Ketenes and Aldehydes
作者:Shi Chen、Mukulesh Mondal、Ahmad A. Ibrahim、Kraig A. Wheeler、Nessan J. Kerrigan
DOI:10.1021/jo500486e
日期:2014.6.6
general catalytic procedure for the formation of β-lactones bearing two stereogenic centers, from disubstituted ketenes and achiral aldehydes. BINAPHANE was found to display excellent enantioselectivity (≥90% ee for eight examples) and good diastereoselectivity (≥90:10 for 13 examples) in catalyzing the formation of β-lactones bearing two stereogenic centers from achiral aldehydes (both aromatic and aliphatic)
在本文中,我们描述了由双取代的烯酮和非手性醛形成带有两个立体中心的β-内酯的一般催化程序。发现BINAPHANE在催化由非手性醛(芳族和脂族)和两个非手性醛形成带有两个立构中心的β-内酯时,表现出优异的对映选择性(对于8个实例≥90%ee)和良好的非对映选择性(对于13个实例≥90:10)。烷基芳基烯酮或二烷基烯酮。在这些反应中观察到偏好形成反式非对映异构体。对于那些其中BINAPHANE失败作为催化剂的反应,三Ñ发现丁基丁基膦是一种有效的非手性亲核催化剂,在外消旋β-内酯的形成中具有良好的收率和非对映选择性。通过31 P NMR光谱监测反应并与在膦催化的乙烯酮均二聚反应中观察到的先前表征的中间体进行比较,获得了有关烯醇中间体参与反应机理的证据。