Enantioselective Copper-Catalyzed Reductive Michael Cyclizations
摘要:
In the presence of siloxanes as stoichiometric reductants, chiral copper-bisphosphine complexes catalyze highly enantioselective reductive Michael cyclizations of substrates containing two alpha,beta-unsaturated carbonyl moieties. The diastereochemical outcome of these reactions is dependent upon whether biaryl- or ferrocene-based chiral bisphosphines are employed.
A Highly Regio- and Stereoselective Cascade Annulation of Enals and Benzodi(enone)s Catalyzed by N-Heterocyclic Carbenes
作者:Xinqiang Fang、Kun Jiang、Chong Xing、Lin Hao、Yonggui Robin Chi
DOI:10.1002/anie.201007144
日期:2011.2.18
Three stereogenic centers in a row: The unconventional activation of enal compounds mediated by an N‐heterocyclic carbene (NHC) has generated three consecutive reactive carbon centers that undergo highly regio‐ and stereoselectiveannulations with di(enone)s to generate benzotricyclic products containing multiple stereogenic centers (see scheme).
Beyond the Corey–Chaykovsky Reaction: Synthesis of Unusual Cyclopropanoids via Desymmetrization and Thereof
作者:Kaushalendra Patel、Uttam K. Mishra、Dipto Mukhopadhyay、S. S. V. Ramasastry
DOI:10.1002/asia.201901108
日期:2019.12.13
Desymmetrization-based protocols for the synthesis of highly functionalized indeno-spirocyclopropanes and cyclopropa-fused indanes have been established through unexpected reactions triggered by the Corey-Chaykovsky reagent. These structures were further elaborated in one step to privileged scaffolds such as fluorenones, indenones, and naphthaphenones. For instance, an acid-catalyzed transformation
Dinuclear zinc synergistic catalytic asymmetric phospha-Michael/Michael cascade reaction: synthesis of 1,2,3-trisubstituted indanes bearing phosphoryl groups
作者:Bing-Kai Tao、Hua Yang、Yuan-Zhao Hua、Min-Can Wang
DOI:10.1039/c9ob00544g
日期:——
A new dinuclear zinc synergistic catalytic asymmetric phospha-Michael/Michael cascade reaction of o-dienones and dialkyl phosphates is reported. This method has been proven to be general and efficient for the formation of a range of chiral 1,2,3-trisubstituted indane compounds containing phosphorus groups in good yields (up to 92%) with excellent stereoselectivities (up to >99% ee and up to >99 : 1
报道了新的邻核二烯和磷酸二烷基酯的双核锌协同催化不对称磷酸-迈克尔/迈克尔级联反应。已证明该方法对于形成一系列含磷基团的手性1,2,3-三取代的茚满化合物是普遍有效的,产率高(高达92%),立体选择性好(ee> 99%,最高> 99:1博士)。通过二维(2D)核Overhauser效应光谱1 H– 1 H NMR实验,确定该产品的相对构型具有反式,反式取代模式。提出了一种可能的机制。
Diastereoselective Synthesis of Indanes via a Domino Stetter−Michael Reaction
作者:Eduardo Sánchez-Larios、Michel Gravel
DOI:10.1021/jo901468h
日期:2009.10.2
N-Heterocyclic carbenes were found to catalyze a domino Stetter−Michael reaction for the synthesis of indanes. The products were obtained in good yield and diastereomeric ratio, allowing access to highly functionalized indanes under mild conditions. In addition, the functional groups present on the indanes could be used for the synthesis of polycyclic pyrroles.
Synthesis of carbocycles by enone-selective reduction using organoiodotin hydride
作者:Toshihiro Suwa、Keita Nishino、Masato Miyatake、Ikuya Shibata、Akio Baba
DOI:10.1016/s0040-4039(00)00388-9
日期:2000.4
By using di-n-butyliodotin hydride (n-Bu2SnIH), carbocycles were prepared from substrates bearing both enone and formyl moieties, where the enone-selective reduction was followed by a diastereoselective intramolecular aldol reaction.