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Hydrosilylation of unsaturated carbon-carbon bonds with hydrosilanes is a very important process to access organosilicon compounds and ranks as one of the most fundamental reactions in organic chemistry. However, catalytic asymmetric hydrosilylation of activated alkenes and internal alkenes has proven elusive, due to competing reduction of carbon-carbon double bond or isomerization processes. Herein, we report a highly enantioselective Si-C coupling by hydrosilylation of carbonyl-activated alkenes using a palladium catalyst with a chiral TADDOL-derived phosphoramidite ligand, which inhibits O-hydrosilylation/olefin reduction. The stereospecific Si-C coupling/hydrosilylation of maleimides affords a series of silyl succinimides with up to 99% yield, >99:1 diastereoselectivity and >99:1 enantioselectivity. The high degree of stereoselectivity exerts remote control of axial chirality, leading to functionalized, axially chiral succinimides which are versatile building blocks. The product utility is highlighted by the enantioselective construction of N-heterocycles bearing up to three stereocenters. Catalytic asymmetric hydrosilylation of internal alkenes has proven elusive due to more favourable double bond reduction or isomerization. Here, the authors show an enantioselective Si-C coupling by hydrosilylation of activated alkenes using a palladium/phosphoramidite catalyst affording axially chiral succinimides. [ABSTRACT FROM AUTHOR]

A palladium‐catalyzed enantioselective intramolecular σ‐bond cross‐exchange between C−I and C−C bonds is realized, providing chiral indanones bearing an alkyl iodide group and an all‐carbon quaternary stereocenter. Pd/TADDOL‐derived phosphoramidite is found to be an efficient catalytic system for both C−C bond cleavage and alkyl iodide reductive elimination. In addition to aryl iodides, aryl bromides can also be used for this transformation in the presence of KI. Density‐functional theory (DFT) calculation studies support the ring‐opening of cyclobutanones occuring through an oxidative addition/reductive elimination process involving PdIV species. [ABSTRACT FROM AUTHOR]

A palladium-catalyzed ketoxime-chelation-assisted enantioselective C–H olefination of 2-arylcyclohex-2-enone oxime ether with a wide range of olefins as coupling partners was developed. Employing ketoxime ether as an efficient directing group, a variety of axially chiral vinyl arenes was synthesized by Pd(ii)-catalyzed C–H functionalization with excellent enantioselectivities (96 → 99% ee) under mild conditions. [ABSTRACT FROM AUTHOR]

Abstract: The development of new strategies or reaction processes that tease new reactivity of functional groups continues to spur synthetic chemists toward innovative solutions that access new compounds. Herein, we find that the silicon‐based bulky group enables a 1,3‐dipolar addition−initiated parallel kinetic resolution (PKR) to occur unexpectedly, leading to the highly enantioselective synthesis of two structurally different types of amino acid derivatives via chemodivergent [3+2] cycloaddition reactions and tandem conjugate addition‐elimination reaction respectively. The resulting and structurally divergent enantioenriched amino acid derivatives that contain four contiguous stereogenic centers and an all‐carbon quaternary center were obtained with up to 99% ee with >95:1 dr and good yields. [ABSTRACT FROM AUTHOR]

Abstract: The first catalytic asymmetric synthesis of highly functionalized pentafluorosulfanylated pyrrolidines is described. The method, based on a 1,3‐dipolar cycloaddition reaction of aryl and heteroaryl‐substituted glycine Schiff bases with pentafluorosulfanyl acrylic esters, gave access to a broad range of pyrrolidines bearing aryl, naphtyl, and heteroaryl groups. By using Xing‐Phos as a catalyst, the corresponding products were obtained in good yields, good to high regioselectivity, and excellent diastereo‐ and enantioselectivities (up to 98 % ee). This methodology allowed the preparation of enantioenriched SF5 compounds for the first time using an enantioselective approach. [ABSTRACT FROM AUTHOR]

Enantioselective synthesis of chiral heterocyclic derivatives is an important and challenging topic in the field of synthetic chemistry. In this work, the first stereocontrolled dimerization-type homo-1,3-dipolar [3+2] cycloaddition reaction of glycine aldimino esters for creating new heterocycles bearing multiple stereogenic centers has been developed through chiral phosphine ligand-involved silver catalysis. A variety of chiral imidazolidines could be obtained with high yields and good diastereoselectivities as well as excellent enantioselectivities by employing Xing-Phos as chiral phosphorus ligand. In addition, the silver/Xing-Phos-catalyzed homo-1,3-dipolar [3+2] cycloaddition reaction is also a facile and novel protocol for catalytic polymerization of bifunctional glycine aldimino esters to give chiral poly(imidazolidine)s with a very narrow molecular weight distribution. [ABSTRACT FROM AUTHOR]

New Schiff bases derived from chiral d -camphor were determined to be effective phosphine ligands for the asymmetric palladium-catalyzed allylic alkylation of activated methylene compounds, the allylic etherification of alcohols, and the allylic amination of primary amines or secondary amines, in which the corresponding products with various functional groups were achieved in good yields with excellent enantioselectivities (up to >99 % ee). Remarkably, the palladium catalyst derived from Schiff base L2 afforded the highest level of enantioselectivity reported to date for allylic substitution reactions, including allylic etherification and allylic amination, which revealed the privileged role of d-camphor-derived Schiff bases in palladium-catalyzed allylic substitution reactions. [ABSTRACT FROM AUTHOR]

In recent years, remarkable progress has been made in the enantioselective silylation of alcohols. Owing to the successful site- and stereoselective functionalization of hydroxy groups, silyl ether formations have evolved from being a simple reaction for functional-group protection into a powerful enantioselective process. In this Minireview, we highlight important recent findings in this emerging field. [ABSTRACT FROM AUTHOR]

A copper catalyst system derived from TaoPhos and CuF2 was used successfully for catalytic asymmetric Huisgen [3+2] cycloaddition of azides and alkynes to give optically pure products containing succinimide- and triazole-substituted quaternary carbon stereogenic centers. The desired products were obtained in good yields (60-80 %) and 85:15 to >99:1 enantiomeric ratio (e.r.) in this click cycloaddition reaction. [ABSTRACT FROM AUTHOR]

An interesting group of multifunctional phosphines (Ar-BINMOL-Phos; Ar-BINMOL=1,1′-binaphthalene-2-α-arylmethanol-2′-ol) with multi-stereogenic centers of axial and sp3-central chirality has been prepared successfully from a single chiral source through a concise synthetic route, in which the neighbouring lithium-promoted [1,2]-Wittig rearrangement proceeding with excellent diastereoselectivity and enantioselectivity is the key process in this approach. Also, in the catalytic alkynylation of aromatic aldehydes with terminal alkynes, the combination of these Ar-BINMOL-Phos ligands with dimethylzinc was found to be an effective catalyst system to afford predominantly the S-configured propargylic alcohols, whereas the additional use of calcium hydride and n-butyllithium along with the same Ar-BINMOL-Phos ligands gave the R-configured products in high yields and excellent enantioselectivities (up to >99% ee). [ABSTRACT FROM AUTHOR]

The fluorination reaction is an important organic transformation for asymmetric synthesis. In this article, we reported the determination of chiral primary amine–based multicatalyst systems for enantioselective fluorination of β-ketoester. Studies on the enantioselective organocatalytic fluorination promoted by cinchona alkaloid–derived chiral primary amines in the absence of various co catalysts revealed that the combined metal salts and organocatalysts resulted in poor conversion and enantioselectivities, whereas the combinational use of L-leucine and QN-NH2as dual primary amine catalysts led to the determination of a novel dual organocatalyst with promising catalytic activity. On the basis of these results, we revealed that the steric environment of the chiral enamine intermediate formed by the condensation of β-ketoester with the chiral primary amine is most responsible for the observed enantioselectivity. [Supplementary materials are available for this article. Go to the publisher's online edition ofSynthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.] [ABSTRACT FROM AUTHOR]

A series of silicon-containing diols are synthesized and used in lipase-catalyzed remote desymmetrization. This synthetic method is valuable in the construction of optically active silicon-stereogenic organosilicon compounds. Good enantioselectivities of the remote desymmetrization was achieved with Candida antarctica lipase B (CAL-B) (up to 90:10 er). [ABSTRACT FROM AUTHOR]

The direct asymmetric aldol reaction catalyzed by the simple and commercially available chiral primary diamines, (1S,2S)-1,2-diphenylethane-1,2-diamine and (1R,2R)-1,2-diphenylethane-1,2-diamine, is presented. The catalyst system is a primary amine with Brønsted acid-catalyzed direct aldol reaction of p-nitrobenzaldehyde and cyclohexanone with high chemo- and stereoselectivity on water, which furnishes the corresponding β-hydroxyketone with up to 94% ee. [ABSTRACT FROM AUTHOR]

The first asymmetric Michael addition of 3-substituted phthalides to nitroolefins promoted by amino acid-incorporating multifunctional catalysts has been developed. The reported method led to the synthesis of 3,3-disubstituted phthalide derivatives in high yields, and in a highly diastereoselective and enantioselective manner. Facile synthesis of a chiral bicyclic lactam has also been demonstrated. [ABSTRACT FROM AUTHOR]

Abstract: A straightforward and practical method for the direct fluorination and chlorination of various β-ketoesters employing a phase-transfer catalyst is developed. The desired products with fluorine/chlorine-substituted quaternary chiral centers are prepared with good to excellent enantioselectivities. [Copyright &y& Elsevier]

The introduction of a halogen-containing chiral quaternary center is best achieved for the bicyclic system (I) under optimized conditions. [ABSTRACT FROM AUTHOR]

Abstract: The highly enantioselective synthesis of warfarin and its analogs was reported in this manuscript. And a cooperative catalysis was observed in asymmetric primary amine-catalyzed Michael reaction for the enantioselective synthesis of warfarin and its analogs, which led to the finding of several cooperative catalyst systems combined with Lewis acid and primary amine, such as LiClO4/DPEN. In this Michael reaction of 4-hydrocoumarin, the cooperative catalyst system (LiClO4/DPEN) resulted in higher levels of stereoselectivity (up to 94%ee). Additionally, the mechanism of the enantioselectivity enhancement in the cooperative catalytic Michael reaction has been investigated by using of ESI-MS and the study of nonlinear effect. [ABSTRACT FROM AUTHOR]

The enantioselective 1,3-dipolar azide cycloaddition affords triazoles with moderate to high enantioselectivity. [ABSTRACT FROM AUTHOR]

The allylic etherification of alcohols and the allylic alkylation of activated methylene compounds, indoles, and aromatic amines proceed with good yields and high enantioselectivity (up to 99% e.e.) employing Fei-Phos as an effective phosphine ligand. [ABSTRACT FROM AUTHOR]

An abstract of the article "Enantioselective Cyanosilylation of Aldehydes Catalyzed by a Multistereogenic Salen-Mn(III) Complex with a Rotatable Benzylic Group as a Helping Hand" by Yun-Long Wei, Wei-Sheng Huang, Yu-Ming Cui, Ke-Fang Yang, Zheng Xu, Li-Wen Xu, is presented.

The synthesis of the chiral ligand is described. [ABSTRACT FROM AUTHOR]

The synthesis of the title air stable multidentate chiral phosphine ligand by a simple protocol and the application of the ligand for the asymmetric Pd-catalyzed allylic esterification of alcohols and silanols is presented. [ABSTRACT FROM AUTHOR]

The novel catalyst is effective in the asymmetric conjugate addition reaction of Et2Zn to enones and tandem silylation and acylation of enantioenriched zinc enolates. [ABSTRACT FROM AUTHOR]

The article presents diagrammatic representation of a molecular assembly of an achiral phosphine and a chiral primary amine used as a supramolecular catalyst for the enantioselective Michael reaction of aldehydes with maleimides.