The active site of the aziridination catalyst derived from either the VANOL or VAPOL ligand and B(OPh)(3) is larger than expected and can accommodate not only significant substitution on the diarylmethyl unit of the imine but also that alkyl (but not perfluorylalkyl) substituents on the aryl groups lead to enhanced rates and enantioselection. The screen of diarylmethyl N-substituents on the imi...

Various aryl bromides or chlorides, including those bearing a free COOH, OH, CONHR, and SO2NHR group, coupled with aryl magnesium or lithium reagents in the presence of 7.5 mol % CoCl2/15 mol % PBu3 and substoichiometric Ti(OEt)4 (40 mol % to ArM) at room temperature in high yields with high chemo- and regioslectivity. This simple reaction represents the first example of Co/Ti cooperative catal...

Herein we report palladium-catalyzed asymmetric benzylic alkylation with 3-aryl oxindoles as prochiral nucleophiles. Proceeding analogously to asymmetric allylic alkylation, asymmetric benzylation occurs in high yield and enantioselectivity for a variety of unprotected 3-aryl oxindoles and benzylic methyl carbonates using chiral bisphosphine ligands. This methodology represents a novel asymmetr...

In the title compound, C(12)H(10)BrN, the dihedral angle between the benzene rings is 52.5 (1)°, whereas the pitch angles, or the angles between the mean plane of each aryl group 'propeller blade' and the plane defined by the aryl bridging C-N-C angle, are 19.6 (2) and 36.2 (3)°. While the N-H group is not involved in hydrogen-bonding inter-actions, the structure exhibits a network of inter-mol...

Excited-state properties of aryl carotenoids, important components of light harvesting antennae of green sulfur bacteria, have been studied by femtosecond transient absorption spectroscopy. To explore effects of the conjugated aryl group, we have studied a series of aryl carotenoids with conjugated phi-ring, chlorobactene, beta-isorenieratene and isorenieratene, and compared them with their non...

The alkaline-earth element bis(trimethylsilyl)amides, [Ae{N(SiMe3 )2 }2 (thf)2 ] [Ae=Mg, Ca, Sr], are effective precatalysts for boron-nitrogen bond formation through the desilacoupling of amines, RR'NH (R=alkyl, aryl; R'=H, alkyl, aryl), and pinBSiMe2 Ph. This reactivity also yields a stoichiometric quantity of Me2 PhSiH and provides the first example of a catalytic main-group element-element ...

ABSTRACT Reactions between (E)-2-aryl-1-cyano-1-nitroethenes and diazafluorene lead to acyclic 2,3-diazabuta-1,3-diene derivatives, instead of the expected pyrazoline systems. DFT calculations suggest that this is a consequence of formation of zwitterionic structure in the first stage of the reaction. It must be noted that this is a specific property of the (E)-2-aryl-1-cyano-1-nitroethenes gro...

A series of new 1-aryl-4-(biarylmethylene)piperazines has been synthesized. These ligands are structurally related to SLV-313, a potential atypical antipsychotic having potent D2 receptor antagonist and 5-HT1A receptor agonist properties. Buchwald-Hartwig coupling reactions of 1-boc-piperazine with appropriate aryl halides and subsequent removal of the boc group rendered arylpiperazines. The re...

Substituted 3,4-dihydro-1,8-naphthyridin-2(1H)-ones have been synthesized with the inverse electron-demand Diels-Alder reaction from 1,2,4-triazines bearing an acylamino group with a terminal alkyne side chain. Alkynes were first subjected to the Sonogashira cross-coupling reaction with aryl halides, the product of which then underwent an intramolecular inverse electron-demand Diels-Alder react...