We report a highly stereoselective synthesis of all-carbon or fluorinated tetrasubstituted alkenes from diazo reagents and fluorinated enol silyl ethers, using C-F bond as a synthetic handle. Cationic Au catalysis plays a key role in this reaction. Remarkable fluorine effects on the reactivity and selectivity was also observed.

A chiral secondary amine phosphoramide was developed and identified as a powerful catalyst for the Mukaiyama-Michael addition of fluorinated enol silyl ethers to tetrasubstituted olefins. The resulting products are obtained with high enantioselectivities and contain a quaternary carbon stereocenter bearing either a difluoroalkyl or monofluoroalkyl group.

Described here is that AuÀCCb onds showed the highest stability under biological conditions,w ith abundant thiols,a nd the best electrochemical performance compared to Au À Sand Au À Se bonds.The new finding was also confirmed by theorical calculations.B ased on this finding, as pecific molecule for recognition of Fe 2+ was designed and synthesized, and used to create as elective and accurate electrochemical sensor for the quantification of Fe 2+ .T he present ratiometric strategy demonstrates high spatial resolution for real-time tracking of Fe 2+ in ad ynamic range of 0.2-120 mM. Finally, amicroelectrode arraywith good biocompatibility was applied in imaging and biosensing of Fe 2+ in the different regions of live mouse brains.U sing this tool, it was discovered that the uptake of extracellular Fe 2+ into the cortex and striatum was largely mediated by cyclic adenosine monophosphate (cAMP) through the CREB-related pathway in the brain of am ouse with Alzheimersd isease.

A rare example of a one-pot process that involves asymmetric triple relay catalysis is reported. The key step is an asymmetric [1,5] electrocyclic reaction of functionalized ketimines. The substrates for this process were obtained in situ in a two-step process that involved the hydrogenation of nitroarenes with a Pd/C catalyst to yield aryl amines and their subsequent coupling with isatin derivatives in a Brønsted acid catalyzed ketimine formation reaction. The electrocyclization was catalyzed by a bifunctional chiral Brønsted base/hydrogen bond donor catalyst. The one-pot process gave the desired products in good yields and with excellent enantioselectivity.

The catalytic asymmetric electrophilic amination has been established as a fruitful methodology for the construction of nitrogen-bearing tetrasubstituted carbon stereocenters, with its roots nourished by the latest achievements in chiral catalysis and synthetic strategies. This review summarizes the recent progresses, briefly discusses the reaction mechanism and challenges in this context, and outlines synthetic opportunities for future development. 3 Amination Reactions Using other Amination Reagents 4 Conclusion

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We report an efficient Mukaiyama-aldol reaction of tryptanthrin with fluorinated enol silyl ethers, which is carried out in methanol without the use of any catalyst. This method is applied to the total synthesis of the difluoro analogues of the natural product Phaitanthrin B.

A rare example of a one-pot process that involves asymmetric triple relay catalysis is reported. The key step is an asymmetric [1,5] electrocyclic reaction of functionalized ketimines. The substrates for this process were obtained in situ in a two-step process that involved the hydrogenation of nitroarenes with a Pd/C catalyst to yield aryl amines and their subsequent coupling with isatin derivatives in a Brønsted acid catalyzed ketimine formation reaction. The electrocyclization was catalyzed by a bifunctional chiral Brønsted base/ hydrogen bond donor catalyst. The one-pot process gave the desired products in good yields and with excellent enantioselectivity.Inspired by the multienzymatic tandem catalytic processes that nature uses for the efficient synthesis of complex molecules, the development of multi-catalyst-promoted asymmetric tandem reactions (MPATR) is of current interest. [1] Aside from the general advantages of tandem catalysis, [2] namely the effectiveness in minimizing waste production, the consumption of energy, labor, and time, and yield losses associated with the purification of intermediates, the use of multiple catalysts, rather than a single catalyst, offers the promise to incorporate more substrates and reaction types to design novel cascade reactions, which are very attractive for building up molecular complexity from simple materials. [1] Over the past decade, much progress has been made in this area, and asymmetric relay catalysis (or sequential catalysis) has been established as a major type of MPATR, [1, 3] which refers to the sequential combination of catalytic reactions, each of which is independently operated by a distinct catalyst, into a one-pot process. Nevertheless, despite remarkable advances in the development of tandem reactions that were achieved by using two metal catalysts, [4] two organocatalysts, [5] or a metal and an organocatalyst, [6] the combination of three distinct catalysts to exploit asymmetric triple relay catalysis is still underdeveloped, although it has already exhibited its powerfulness in tackling some synthetic challenges. [7] On the other hand, the ever-increasing demand in chemical biology and medicinal research for synthetic libraries derived from privileged scaffolds requires the development of new synthetic methods that enable the construction of libraries of optically active compounds with polycyclic structures. [8] In particular, efficient stereoselective syntheses of spirocyclic compounds are very much in demand. [9] Therefore, the exploration of asymmetric triple relay catalysis for the facile construction of spirocyclic compounds from simple materials is highly desirable. Herein, we report an unprecedented example of asymmetric triple replay catalysis, which integrates palladium, Brønsted acid, and bifunctional chiral Brønsted base/hydrogen bond donor catalysis, and we demonstrate its effectiveness in the highly enantioselective synthesis of oxindole-based spirocyclic indolines through a onepot sequence that involves hydrogenation, ketimine format...