Copper/TEMPO-Promoted Denitrogenation/Oxidation Reaction for Synthesis of Primary α-Ketoamides Using α-Azido Ketones.

A copper(II)-promoted denitrogenation/oxidation reaction for the preparation of primary α-ketoamides was developed using α-azido ketones as a substrate and TEMPO as an oxidant. α-Azido ketones were denitrogenated in situ to form an imino ketone intermediate, which underwent a radical addition process and radical migration to form α-ketoamides. It is worth noting that the imino ketone intermediate is the key to this reaction.

Rh(III)-Catalyzed Tandem Reaction Access to (Quinazolin-2-yl)methanone Derivatives from 2,1-Benzisoxazoles and α-Azido Ketones.

A Rh(III)-catalyzed tandem reaction for the synthesis of (quinazolin-2-yl)methanone derivatives has been explored from 2,1-benzisoxazoles and α-azido ketones. The transformation involves Rh(III)-catalyzed denitrogenation of α-azido ketones, aza-[4 + 2] cycloaddition, ring opening, and dehydration aromatization processes. Notably, the aza-[4 + 2] cycloaddition of an imine rhodium complex intermediate with 2,1-benzisoxazoles is the key to this reaction.

Metal-Free Cascade [4 + 1] Cyclization Access to 4-Aryl-NH-1,2,3-triazoles from N-Tosylhydrazones and Sodium Azide.

A molecular iodine-mediated coupling cyclization reaction for the synthesis of 4-aryl-NH-1,2,3-triazoles has been developed from N-tosylhydrazones and sodium azide. This metal-free cascade [4 + 1] cyclization reaction could rapidly synthesize valuable compounds via a sequential C-N and N-N bond formation. Mechanistic studies demostrate that the nitrogen atoms of the 1,2,3-triazoles are not entirely from sodium azide.

Biliopancreatic route for effective viral transduction of pancreatic islets.

OBJECTIVE: Pancreatic islets are notoriously difficult to efficiently transduce genes with viruses whether in vivo or ex vivo, the latter only transducing superficial layers of the islet. To improve efficiency of transduction, we explored surgical approaches to virus delivery in vivo. METHODS: A technique was developed for retrograde surgical perfusion into the rat biliopancreatic duct with a test adenovirus containing a construct coexpressing green fluorescent protein, the latter for detection of infected cells. RESULTS: Pancreatic islets isolated after acute pancreatic infusion and cultured for 2 days showed expression in the entire islet and in almost all islets. When rats were recovered from the surgery, and then islets isolated at 1 and 8 weeks after surgery, we continued to see extensive islet green fluorescent protein expression, albeit at more reduced levels at 8 weeks. CONCLUSIONS: This strategy of surgical pancreatic ductal perfusion of viruses is an effective way to transduce or reduce gene expression in pancreatic islets for both acute and chronic study.

[TGF-beta1 in allograft and long-term renal function].

OBJECTIVE: To determine the relation between transforming growth factor beta1 (TGF-beta1) in allograft and long-term renal function. METHODS: Urine TGF-beta1 relative concentration (divided by urine creatinine) was tested in 168 recipients whose renal function was normal between August 1, 2000 and March 31, 2001. Twenty patients with higher urine TGF-beta1 relative concentrations formed Group A, and another 20 patients with lower urine TGF-beta1 formed Group B. In both groups biopsies were carried out in 15 cases and 12 cases respectively, and TGF-beta1 in the biopsis was tested by immunofluorescence. Blood TGF-beta1 concentrations in the 2 groups were also tested. Three years later, the renal function was compared between the 2 groups. Biopsies were carried out in renal recipients whose creatinine was higher than that of the normal. RESULTS: Blood TGF-beta1 concentrations in the 2 groups were not different significantly; 3 years after the transplantation, there was more loss of renal function and more chronic allograft nephropathy (CAN) cases in Group A than in Group B. Expression of TGF-beta1 in the allografts was higher in Group A than in Group B. The differences in the 2 groups were significant. CONCLUSION: The findings suggest that the higher expression of TGF-beta1 in the allografts is associated with the lower long-term survival rate of kidney graft. The level of urine TGF-beta1 after the renal transplantation can predict the long-term renal function.