By a sequence comprising asymmetric hydroboration, boron-zinc exchange, and transmetalation with copper, allylations, alkynylations, and allenylations of unsaturatedketals or acetals can be performed with good enantioselectivities (see scheme, (-)-IpcBH2 =(-)-isopinocampheylborane, TMS=Me3 Si). The products correspond to a formal Michael addition with inversion of polarity.
[EN] BI- AND TRICYCLIC COMPOUNDS FOR USE AS AROMA CHEMICALS<br/>[FR] COMPOSÉS BI- ET TRICYCLIQUES DESTINÉS À ÊTRE UTILISÉS EN TANT QUE PRODUITS CHIMIQUES AROMATIQUES
申请人:BASF SE
公开号:WO2020127305A1
公开(公告)日:2020-06-25
The present invention relates to bi-and tricyclic compounds of the general formula (I) (I) wherein the dashed lines independently of each other represent a single or a double bond, X represents a group of the formulae X1 to X3 wherein the asterisk denotes the point of attachment to the rest of the molecule, R1a and R1b, independently of each other, are selected from hydrogen or methyl, or R1a together with R1b form a methylene or ethylene group, R2, R3a, R3b, R4, R5a and R5b, independently of each other, are selected from hydrogen or methyl, R6 is selected from hydrogen, methyl or ethyl, and R7 is methyl or ethyl, to a method of preparing said compounds, to the use of a bi- or tricyclic compounds or of mixtures of two or more bi- and tricyclic compounds or of a stereoisomer thereof or of a mixture of two or more stereoisomers thereof as aroma chemicals; to the use of a bi- or tricyclic compound for modifying the scent character of a fragranced composition; to an aroma chemical composition containing a bi- or tricyclic compound or a mixture of two or more bi- and tricyclic compounds or of a stereoisomer thereof or of a mixture of two or more stereoisomers thereof; and to a method of preparing a fragranced composition or for modifying the scent character of a fragranced composition, comprising incorporating a bi- or tricyclic compound or a mixture of two or more bi- and tricyclic compounds or of a stereoisomer thereof or of a mixture of two or more stereoisomers thereof into said composition.
Three's a crowd: The combination of a Brønstedacid and a hydrogen‐bond donor cocatalyst was found to promote various ionic [2+4] cycloadditions under mild reaction conditions (see scheme; Ts=4‐toluenesulfonyl). Thiophosphoramides are the most effective cocatalysts because of the stronger counterion activation effect resulting from three, rather than two, hydrogen bonds involved in anion binding.
describe the synthesis of a new family of chiral bridled porphyrins. They were obtained by reaction between pyrrole and a chiral 2-formylcyclohexanol derivative. Thanks to an enzymatic kinetic resolution method, these compounds were obtained in both enantiomeric forms. This resolution method allows easy synthesis of chiral precursors in high yield and on large scale. These newporphyrins exhibited an
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。