Acid-Catalyzed Cyclization of Epoxyallylsilanes. An Unusual Rearrangement Cyclization Process
作者:Asunción Barbero、Pilar Castreño、Francisco J. Pulido
DOI:10.1021/ol035297v
日期:2003.10.1
synthesis of epoxyallylsilanes bearing the phenyldimethylsilyl group is reported that involves silylcupration of allene, conjugate addition to enones, and sulfur-ylide-mediated epoxidation. The Lewis acid-catalyzed cyclization of these substrates is presented. The expected normal products derived from 5-exo and/or 6-endo attack are not observed; instead, methylenecyclohexanols resulting from a tandem rea
Synthesis of 3-Methylenecyclohexan-1-ols by Lewis Acid Catalyzed Cyclization of (Epoxy-allyl)silanes
作者:Francisco J. Pulido、Asunción Barbero、Pilar Castreño
DOI:10.1002/ejoc.200901263
日期:2010.3
A newroute for the synthesis of (epoxy-allyl)silanes bearing the PhMe 2 Si group has been developed and their acid-catalyzed cyclization studied. The so-called normal products derived from 5-exo or 6-endo attack were never obtained. On the contrary, an interesting tandem rearrangement/cyclization process was observed, which selectively led to 3-methylenecyclohexan-1-ols. A mechanism is proposed to
已经开发了一种合成带有 PhMe 2 Si 基团的(环氧-烯丙基)硅烷的新途径,并研究了它们的酸催化环化。5-exo 或 6-endo 攻击衍生的所谓正常产物从未得到过。相反,观察到了一个有趣的串联重排/环化过程,它选择性地产生了 3-亚甲基环己-1-醇。提出了一种机制来解释这种串联反应。环化过程的立体选择性取决于催化剂的性质。
One-Pot Synthesis of 2,7-Dioxabicyclo[2.2.1]heptanes from Oxoallylsilanes
作者:Francisco J. Pulido、Asunción Barbero、Raquel Abad
DOI:10.1002/ejoc.201101087
日期:2011.12
oxoallylsilanes is described. The mechanism of this tandem reaction is a sequential epoxidation of the allylsilane moiety and subsequent intramolecular cyclization. This simple protocol allows the synthesis of epoxy-bridged tetrahydropyrans from allene in two high-yielding steps: silylcupration of allene (followed by capture of the intermediate cuprate with enones) and treatment of the oxoallylsilanes thus obtained
Efficiency of Acid- and Mercury-Catalyzed Cyclization Reactions in the Synthesis of Tetrahydrofurans from Allylsilyl Alcohols
作者:Francisco J. Pulido、Asunción Barbero、Patricia Val、Alberto Diez、Alfonso González-Ortega
DOI:10.1002/ejoc.201200666
日期:2012.9
The scope of the acid-catalyzed and mercury-catalyzed cyclization reactions of allylsilyl alcohols is described. This methodology has been found to be an efficient approach to the synthesis of highlysubstitutedtetrahydrofurans. The stereoselectivity of the cyclization is dependent both on the substitution of the starting alcohol and on the catalyst. A plausible mechanism has been proposed that is
Seven-Membered Ring Formation from Cyclopropanated Oxo- and Epoxyallylsilanes
作者:Francisco J. Pulido、Asunción Barbero、Pilar Castreño
DOI:10.1021/jo200705u
日期:2011.7.15
A useful strategy for cycloheptane annulations from oxo- and epoxyallylsilanes, prepared by silylcupration of allenes, has been developed, and their application to the stereoselective synthesis of 4-methylenecycloheptan-1-ols is of great potential in the construction of seven-membered ring natural products presented.