Arylation Of Ketimines Research Articles

Enantioselective Organocatalytic Addition of Nitromethane to Trifluoromethyl Aryl Ketimines Promoted by Electron‐Rich Bifunctional Iminophosphoranes

AbstractThiourea‐based iminophosphorane (BIMP) organocatalysts featuring SPhos‐ or BIDIME phosphine units have been developed and successfully applied in the asymmetric addition of nitromethane to N‐Boc‐protected trifluoromethyl aryl ketimines. α‐Trifluoromethyl β‐nitroamines were obtained in 40–82% isolated yields and 80–95% enantioselectivities. A careful evaluation of the catalytic activity of BIMPs indicates that the catalysts derived from the combination via Staudinger reaction of a chiral 1,2‐amino alcohol‐derived thiourea‐organoazide with electron‐rich phosphines, promote the aza‐Henry reaction on fluorinated ketimines with the highest enantioselectivity, leading to the amine featuring a tetrasubstituted stereocenter in up to 95% ee. The reaction was performed also on gram scale, without loss of enantioselectivity.magnified image

Air‐Stable Manganese(I)‐Catalyzed C−H Activation for Decarboxylative C−H/C−O Cleavages in Water

AbstractThe decarboxylative C−H/C−O functionalization was accomplished by air‐ and water‐tolerant manganese(I) catalysis. The versatile C−H allylation occurred by facile organometallic C−H metalation on indoles, arenes, amino acids and synthetically meaningful aryl ketimines with ample substrate scope and high levels of chemo‐, site‐ and regio‐selectivity.

Air-Stable Manganese(I)-Catalyzed C-H Activation for Decarboxylative C-H/C-O Cleavages in Water.

The decarboxylative C-H/C-O functionalization was accomplished by air- and water-tolerant manganese(I) catalysis. The versatile C-H allylation occurred by facile organometallic C-H metalation on indoles, arenes, amino acids and synthetically meaningful aryl ketimines with ample substrate scope and high levels of chemo-, site- and regio-selectivity.

Ortho-C-H Benzylation of Aryl Imines with Benzyl Phosphates under Cobalt-Pyphos Catalysis.

Ortho-C-H benzylation of aryl ketimines with benzyl phosphates is achieved with the aid of a catalytic system consisting of a cobalt(II) salt, a phosphine/pyridine bidentate ligand, and a Grignard reagent under room-temperature conditions, affording a variety of diarylmethanes bearing o-acetyl or -acyl groups in moderate to good yields. Owing to the versatility of the o-acetyl group, the reaction opens useful synthetic routes to polycyclic compounds such as unsymmetrical anthracene, anthracenone, and anthraquinone derivatives.

ChemInform Abstract: Rhodium‐Catalyzed Dynamic Kinetic Asymmetric Transformations of Racemic Allenes by the [3 + 2] Annulation of Aryl Ketimines.

AbstractThe title reaction proceeds in a high regio‐, enantio‐, and diastereoselective manner for the allene incorporation.

Rhodium‐Catalyzed Dynamic Kinetic Asymmetric Transformations of Racemic Allenes by the [3+2] Annulation of Aryl Ketimines

Racemisierung erforderlich: Eine Rhodium(I)-katalysierte C-H-Aktivierung, die von ungeschützten Ketiminen dirigiert wird, führt zu einer selektiven [3+2]-Cycloaddition mit Allenen und eröffnet einen Zugang zu hoch substituierten Indenylaminen. Die Reaktion verläuft über eine dynamisch-kinetische asymmetrische Umsetzung von racemischen Allenen. Der Katalysator kontrolliert sowohl die Enantio- und Diastereoselektivität als auch die Regioselektivitäten der C-H-Aktivierung und des Allen-Einbaus sowie das E/Z-Verhältnis. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Rhodium‐Catalyzed Dynamic Kinetic Asymmetric Transformations of Racemic Allenes by the [3+2] Annulation of Aryl Ketimines

Racemization required: Rhodium(I)-catalyzed C-H activation directed by unprotected ketimines initiates selective [3+2] cycloaddition with allenes, providing access to highly substituted indenylamines. The reaction proceeds through the dynamic kinetic asymmetric transformation of racemic allenes. The catalyst controls the enantio- and diastereoselectivity, the regioselectivities of the C-H activation and allene incorporation, as well as the E/Z ratio.

ChemInform Abstract: Catalytic C—H Bond Arylation of Aryl Imines and Oxazolines in Water with Ruthenium(II)—Acetate Catalyst.

AbstractA convenient protocol is developed for the selective ortho‐diarylation of aryl‐aldimines, aryl ketimines, and phenyl oxazines with aryl bromides.

N‐Heterocyclic Carbene‐Catalyzed Homoenolate Additions with N‐Aryl Ketimines as Electrophiles: Efficient Synthesis of Spirocyclic γ‐Lactam Oxindoles

In pole position: A simple and efficient approach to spirocyclic γ-lactam oxindoles by the N-heterocyclic carbene catalyzed addition of homoenloate equivalents to N-aryl isatinimines has been developed (see scheme). The use of N-aryl isatinimines as electrophiles in the NHC-catalyzed umpolung reaction of α,β-unsaturated aldehydes is demonstrated for the first time.

Practical Synthesis of N-Aryl-o-hydroxyaryl Ketimines

Heating o-hydroxyacetophenones and anilines under solvent-free conditions afforded the corresponding aryl ketimines in good to excellent yields.

Enantioselective Rhodium(I)‐Catalyzed [3+2] Annulations of Aromatic Ketimines Induced by Directed CH Activations

Triple selectivity: Highly substituted indenylamines can be obtained with high enantioselectivity by formal [3+2] additions of aryl ketimines with internal alkynes. These rhodium(I)-catalyzed processes proceed by selective CH activation of one of the two arene substituents, regioselective carbometalation of the alkyne, and enantioselective addition across the imine.

Syn‐Selective Rhodium(I)‐Catalyzed Allylations of Ketimines Proceeding through a Directed CH Activation/Allene Addition Sequence

Rhodium(I)-catalyzed C-H functionalization of aryl ketimines and subsequent carborhodation of a terminal allene resulted in the formation of allyl rhodium intermediates, which underwent allylation of the imine to give cyclized products, e.g., I, with high regioselectivity and diastereoselectivity. Preliminary attempts to develop an enantioselective variant were also successful.

Oxidative Rearrangement of Ketimines to Amides by MCPBA and BF3×OEt2.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Oxidative Rearrangement of Ketimines to Amides by MCPBA and BF3·OEt2

Several amides were obtained by an efficient method from the corresponding alkyl aryl ketimines in high yields. Ketimines are readily prepared from the corresponding ketones. This procedure involves the oxidation of alkyl aryl ketimines with MCPBA with BF3·OEt2. In this reaction, only aryl group of alkyl aryl ketimines was migrated to the electron deficient nitrogen atom.

Organoboron compounds 334. Complexes of trialkylboranes with ketimines

1. We have synthesized and characterized complexes of trialkylboranes with diaryl ketimines and alkyl aryl ketimines. 2. We have used11B NMR spectroscopy to show that complexes of tri-n-butylborane with diaryl ketimines are less stable than those with alkyl aryl ketimines. The latter in turn are more stable than coordination compounds of tri-n-butylborane with secondary amines.

Organosilicon compounds XVI. Preparation of various 2‐(5‐trimethylsilyl)thienyl aryl ketimines and ketones

Organosilicon compounds XVI. Preparation of various 2‐(5‐trimethylsilyl)thienyl aryl ketimines and ketones