Vascular Malformation Involving the Brachial Plexus: A Case Report and Review of Literature.

Introduction: Vascular anomalies, comprising up to 4.5% of the general population, are aberrations occurring during vascular development. Vascular abnormalities are frequently identified in children and frequently exhibit characteristics similar to nerve sheath tumors. We report a case of 16 years old boy with a arterio-venous (AV) malformation (AVM) affecting the brachial plexus. We discuss the clinical features, diagnosis, treatment, and histopathological findings in this patient and review the relevant literature. Case Report: A 16- year-s old boy presented with pain, paresthesia, swelling, and reduced grip strength of the hand. Radiological investigations revealed a vascular lesion encasing C5, C6 nerve roots and displacing the C7 root. Near total surgical excision of the lesion was done with preservation of nerve. Histopathology confirmed arteriovenous AVMmalformation with distinct features. Conclusion: High-resolution ultrasound is crucial for diagnosing soft- tissue vascular anomalies. Surgeons well versed in micro surgical skill play a vital key role in minimizing neural deficits. In the case of vascular malformations of brachial plexus, near total excision is the most favorable option.

Rhodium(II)-catalyzed nondirected oxidative alkenylation of arenes: arene loading at one equivalent.

A bimetallic Rh(II) catalyst promoted the C-H alkenylation of simple arenes at 1.0 equivalent without the use of a directing group. A phosphine ligand as well as cooperative reoxidation of Rh(II) with Cu(TFA)2 and V2O5 proved essential in providing monoalkenylated products in good yields and selectivities, especially with di- and trisubstituted arenes.

Pd(II)-catalyzed enantioselective C-H activation/C-O bond formation: synthesis of chiral benzofuranones.

Pd(II)-catalyzed enantioselective C-H activation of phenylacetic acids followed by an intramolecular C-O bond formation afforded chiral benzofuranones. This reaction provides the first example of enantioselecctive C-H functionalizations through Pd(II)/Pd(IV) redox catalysis.

Asymmetric NHC-catalyzed synthesis of α-fluoroamides from readily accessible α-fluoroenals.

The scope of the NHC-redox amidation has been expanded to include a variety of α,ß-unsaturated aldehydes, including α-fluoro α,ß-unsaturated aldehydes which give rise to enantioenriched α-fluoroamides in good to excellent yield and enantioselectivity (up to 97% ee). Enantioenriched amines may be elaborated to either diastereomer of the product in high diastereoselectivity (up to 99:1). Functionalization of the amide products to amines and fluorohydrins is also demonstrated with retention of enantioenrichment at the fluorine stereocenter.

Exploiting Acyl and Enol Azolium Intermediates via NHeterocyclic Carbene Catalyzed Reactions of Alpha-Reducible Aldehydes.

N-heterocyclic carbenes are well known for their role in catalyzing benzoin and Stetter reactions: the generation of acyl anion equivalents from simple aldehydes to react with a variety of electrophiles. However, when an aldehyde bearing a leaving group or unsaturation adjacent to the acyl anion equivalent is subjected to an NHC, a new avenue of reactivity is unlocked, leading to a number of novel transformations which can generate highly complex products from simple starting materials, many of which are assembled through unconventional bond disconnections. The field of these new reactions - those utilizing α-reducible aldehydes to access previously unexplored catalytic intermediates - has expanded rapidly in the past eight years. This review aims to provide the reader with a historical perspective on the underlying discoveries that led to the current state of the art, a mechanistic description of these reactions, and a summary of the recent advances in this area.

N-Heterocyclic carbene catalyzed asymmetric hydration: direct synthesis of alpha-protio and alpha-deuterio alpha-chloro and alpha-fluoro carboxylic acids.

Asymmetric hydration of alpha,alpha-dichloro aldehydes and alpha-halo enals via a NHC-catalyzed redox process to yield enantioenriched alpha-chloro and alpha-fluoro carboxylic acids is described herein. The developed reaction allows for installation of an alpha-deuterium to give rise to enantioenriched alpha-deutero alpha-halo acids using D(2)O as the deuteron source.

Nucleophilic carbene catalyzed synthesis of 1,2 amino alcohols via azidation of epoxy aldehydes.

We report herein a nucleophilic carbene catalyzed redox azidation of epoxyaldehydes. The intermediate beta-hydroxy acyl azides undergo thermal Curtius rearrangement followed by trapping with excess azide to form carbamoyl azides or, in a complementary sequence, by the hydroxy group to form oxazolidinones. Both products are formed in modest to good yields and diastereoselectivities. The use of an enantioenriched triazolium catalyst leads to modest asymmetric induction.

Discovery and optimization of pyridazinone non-nucleoside inhibitors of HIV-1 reverse transcriptase.

A series of benzyl pyridazinones were evaluated as HIV-1 non-nucleoside reverse transcriptase inhibitors (NNRTIs). Several members of this series showed good activity against the wild-type virus and NNRTI-resistant viruses. The binding of inhibitor 5a to HIV-RT was analyzed by surface plasmon resonance spectroscopy. Pharmacokinetic studies of 5a in rat and dog demonstrated that this compound has good oral bioavailability in animal species. The crystal structure of a complex between HIV-RT and inhibitor 4c is also described.