Pd-Catalyzed Carbonylation of Vinyl Triflates To Afford α,β-Unsaturated Aldehydes, Esters, and Amides under Mild Conditions
作者:Shaoke Zhang、Helfried Neumann、Matthias Beller
DOI:10.1021/acs.orglett.9b00765
日期:2019.5.17
An efficient and general protocol for the synthesis of α,β-unsaturated aldehydes, esters, and amides via carbonylation of vinyl triflates including derivatives of camphor, ketoisophorone, verbenone, and pulegone was developed. Crucial for these transformations is the use of a specific palladium catalyst containing a pyridyl-substituted dtbpx-type ligand. This procedure also allows for an easy access
开发了一种有效的通用方案,可通过乙烯基三氟甲磺酸酯的羰基化反应合成α,β-不饱和醛,酯和酰胺,包括樟脑,酮异佛尔酮,马鞭草酮和普乐酮。这些转化的关键是使用含有吡啶基取代的d t bpx型配体的特定钯催化剂。该方法还使得容易从相应的酮获得二羰基化产物。
Room-temperature Pd-catalyzed methoxycarbonylation of terminal alkynes with high branched selectivity enabled by bisphosphine-picolinamide ligand
In the work reported herein, the concise and enantioselective total synthesis of the Schizozygine alkaloid (−)-strempeliopine was developed. This synthetic strategy featured the palladium-catalyzed decarboxylative asymmetric allylic alkylation of N-benzoyl lactam to set up the absolute configuration at the C20 position, a highly diastereoselective one-pot Bischler–Napieralski/lactamization and iminium
targeted drug delivery). Herein, we report a straightforward synthesis of wavelength‐selective multifunctional photoinitiators (PIs) that contain a bisacylphosphane oxide (BAPO) group and an α‐hydroxy ketone moiety within one molecule. By using three different wavelengths, these photoactive groups can be selectively addressed and activated, thereby allowing the synthesis of ABC‐type miktoarm star polymers
The first addition of photoinitiator radicals formed by the photolysis of a bisacylphosphine oxide photoinitiator to an acrylate double bond proceeds reversibly (see scheme; R1=tBu, H; R2=MeOC(O), BuOC(O)). Moreover, hydrogen transfer between substituted benzoyl radicals and the growing radical chain explains the formation of aldehydes in such a transformation.
由双酰基氧化膦光引发剂的光解形成的丙烯酸酯双键的光引发剂基团的首次添加可逆地进行(参见方案; R 1 = t Bu,H; R 2 = MeOC(= O),BuOC(= O))。此外,取代的苯甲酰基基团和增长的基团链之间的氢转移解释了这种转化过程中醛的形成。