The Combinatorial Approach to Asymmetric Hydrogenation: More Miles out of Monophos

1Introduction In custom manufacturing time-to-market is of overriding importance. Thus, asymmetric hydrogenation will be applied only if an appropriate catalyst can be found in a very short period of time. For this reason we have build up a full-scale capability for High Throughput Experimentation, encompassing several robot systems. As ligand synthesis was the last remaining barrier we have explored, together with the University of Groningen, the use of simple monodentate ligands, such as MonoPhosTM. These ligands can be synthesised in two chemical steps, from BINOL, PCl3 and an amine.Surprisingly, very high enantioselectivities can be obtained in the asymmetric hydrogenation of α-and β-dehydro-amino acids and esters, aromatic enamides, itaconic acid and ester[1]. See Scheme 1 and 2(at page 830).     

三苯甲基保护的巯烷臂寡核苷酸的合成及荧光标记

用三苯甲基巯基乙醇与氯化甲氧基吗啉亚磷酰胺连接得到一种亚磷酰胺试剂（Ⅲ）。用该试剂通过固相合成仪合成了5′末端巯烷基修饰的寡核苷酸，用Ag^ 脱去巯基的三苯甲基保护后与ω-碘已基修饰的荧光基因反应，得到相应的荧光标记寡核苷酸探针，设计的lmbH筛选探针与质粒DNA进行杂交，杂交结果验证了这种标记的实用性，灵敏度不达1pmol。     

Enantioselective Rh-catalyzed hydrogenation of N-acyl dehydroamino esters and enamides with monodentate phosphoramidite ligands

Chiral monodentate phosphoramidite ligands were conveniently prepared from 1,1′-bi-2-naphthol (BINOL) and (S)-pyrrolidine in good yields, which were effective chiral ligands in the enantioselective rhodium-catalyzed hydrogenation of dehydroamino esters and enamides at low hydrogenation pressure. High conversion rate (up to 99% for dehydroamino esters and enamides) and good enantioselectivity (up to 96.3% ee for dehydroamino esters and 91.7% ee for enamides) were obtained. Biography: LI Xinsheng (1970–), male, Associate professor, Ph. D., research direction: asymmetric synthesis.     

苯并-P-胺基-2-磷杂-1,3-二氧杂环己烷协同下钯催化的Suzuki-Miyaura反应

以廉价、易得的三氯化磷、仲胺、2-羟基苯甲醇为原料,合成了6种多功能苯并-P-胺基-2-磷杂-1,3-二氧杂环己烷类亚磷酰胺配体。在温和条件下,将其应用到钯催化的Suzuki-Miyaura偶联反应中。配体L4表现出了较好的活性,产物的最大分离收率达到了93%。     

The Combinatorial Approach to Asymmetric Hydrogenation： More Miles out of Monophos

1 Introduction In custom manufacturing time-to-market is of overriding importance. Thus, asymmetric hydrogenation will be applied only if an appropriate catalyst can be found in a very short period of time. For this reason we have build up a full-scale capability for High Throughput Experimentation, encompassing several robot systems. As ligand synthesis was the last remaining barrier we have explored, together with the University of Groningen, the use of simple monodentate ligands, such as …