Aldehydes and ketones form intermediate π complexes with the Gilman reagent, Me2CuLi, at low temperatures in tetrahydrofuran.

Typical aldehydes and ketones form π complexes with Me2CuLi at low temperatures in tetrahydrofuran. They range in stability from fleeting intermediates at -100 °C to entities that persist up to -20 °C. Three subsequent reaction pathways have been identified.

First X-ray crystal structure and internal reference diffusion-ordered NMR spectroscopy study of the prototypical Posner reagent, MeCu(SPh)Li(THF)3.

Grow slow: The usual direct treatment of MeLi and CuSPh did not yield X-ray quality crystals of MeCu(SPh)Li. An indirect method starting from Me2CuLi⋅LiSPh and chalcone afforded the desired crystals by the slow reaction of the intermediate π-complex (see scheme). This strategy produced the first X-ray crystal structure of a Posner cuprate. A complementary NMR study showed that the contact ion pair was also the main species in solution.

Rapid injection NMR reveals η3 'π-allyl' Cu(III) intermediates in addition reactions of organocuprate reagents.

By using rapid injection NMR, it has now been possible to prepare and characterize the η(3) 'π-allyl' copper(III) intermediate that has been proposed for addition reactions of organocopper(I) reagents and α,ß-unsaturated carbonyl compounds.

Minimization of organocuprate complexity through self-organization: remarkable orientation effect in mixed cuprate π complexes.

They "know" where to go: a powerful orientation effect has been observed in complexes of mixed organocuprates [R(T)R(NT)CuLi] and substrates with C-C, C-N, and C-S double bonds (see scheme; Th=thienyl). The preferred geometry of the intermediate complex sets up the facile addition of R(T) to the double bond, rather than addition of the "dummy ligand", R(NT) .

Argentate(i) and (iii) complexes as intermediates in silver-mediated cross-coupling reactions.

Despite the potential of silver to mediate synthetically valuable cross-coupling reactions, the operating mechanisms have remained unknown. Here, we use a combination of rapid-injection NMR spectroscopy, electrospray-ionization mass spectrometry, and quantum chemical calculations to demonstrate that these transformations involve argentate(i) and (iii) complexes as key intermediates.

Our experience in using the brachial venae comitantes as a native vascular access for hemodialysis.

A native arteriovenous fistula is the preferred vascular access for patients on long-term hemodialysis. In the absence of suitable superficial veins, the deep venous system can be used. We intend to present our experience in using the brachial venae comitantes (VC) to create a native arteriovenous fistula. From January 2012 to December 2014, we utilized the brachial vena comitantes to create 12 arteriovenous fistulae. Data from these 12 subjects were analyzed retrospectively to produce this case series. The average age of our subjects was 55.6 years. Forty-two percent of the subjects were women. Fifty percent of the subjects had diabetes mellitus and 58% had hypertension. We achieved a functional patency rate of 58% at 1 month's follow up after maturation. The brachio-brachial vena comitans fistula is a safe and plausible option in patients with no other suitable veins for a native fistula, more so in the hands of experienced surgeons. The longer time to cannulation has to be taken into consideration when creating a VC fistula. In suitable patients with end-stage renal disease, it can delay the use of an arteriovenous graft or a tunneled central venous catheter.

π-Complexes from acyl cyanides and lithium dimethylcuprate(I).

Rapid injection of pyruvonitrile or benzoyl cyanide into solutions of Me2CuLi in THF-d8 at -100 °C gave complexes that were stable at this temperature. 1D NMR with multiply labelled substrates ((13)C/(15)N) and 2D NMR ((1)H/(13)C) identified them as the first cuprate-carbonyl π-complexes.