General scope of 1,3-dioxolanation of .alpha.,.beta.-unsaturated aldehydes with 1,2-bis(trimethylsilyloxy)ethane and trimethylsilyl trifluoromethanesulfonate
describe a method to improve the yield and the kinetics of the difficult syntheses of α,β-unsaturated porphyrins, which enabled us to obtain a new chiral porphyrin derived from (S)-(−)-perillaldehyde in a 6% yield. Variable temperature NMR experiments on the free base, the zinc(II) and the nickel(II) complexes showed that two distinct and consecutive dynamic processes linked with the meso substituents
我们描述了一种提高产量和困难合成α,β-不饱和卟啉的动力学的方法,该方法使我们能够以6%的产率获得衍生自(S)-(-)-紫苏醛的新手性卟啉。在游离碱,锌(II)和镍(II)配合物上进行的可变温度NMR实验表明,发生了与介孔取代基旋转相关的两个不同且连续的动力学过程。这些过程可以分析为随温度变化而形成的构象异构体。更高的值被发现为所述取代基的转动自由能(通过可变温度测量1相比,这些其它等效卟啉的1 H NMR)等内消旋四苯基卟啉或内消旋-四环己基卟啉。
An Efficient Method for the Acetalization of .alpha.,.beta.-Unsaturated Aldehydes
作者:Ta-Jung Lu、Jyh-Ferng Yang、Lij-Jyi Sheu
DOI:10.1021/jo00114a055
日期:1995.5
Regioselective Semihydrogenation of Dienes
作者:Thomas J. A. Graham、Thomas H. Poole、Charles N. Reese、Brian C. Goess
DOI:10.1021/jo200262r
日期:2011.5.20
A one-pot, three-step strategy for the regioselective semihydrogenation of dienes is described. This procedure uses 9-BBN-H as a temporary protective group for alkenes. Yields range from 55% to 95%, and the reaction is tolerant of a variety of common functional groups. Additionally, the final elimination step of the sequence can be replaced with a peroxide-mediated alkylborane oxidation, generating regioselectively semihydrogenated product alcohols.