A route to benzodithiophene systems by exploiting a ligand-free Suzuki-Miyaura coupling reaction in deep eutectic solvents

Benzo[1,2-b:4,3-b\u2019]dithiophene (BDT) and its derivatives belong to an interesting class of thiophene-based aromatic \uf070-conjugated compounds that are widely studied as functional organic materials inserted, for instance, as units in mono and polydisperse oligomers [1], or as \uf070-spacers in push-pull organic chromophores for photovoltaic applications [2]. Moreover, BDTs are key intermediates for the synthesis of inherent chiral tetrathia[7]helicenes, which are an attractive class of heterohelicenes with unique physicochemical and chiroptical properties due to their helix-like structure [3]. Thus, BDT is a key starting molecule which can allow access to more complex and interesting systems through a selective and judicious functionalization of the \uf061 and \uf062-positions of the terminal thiophene rings. Building on our recent studies on the synthesis and functionalization of BDTs [4], we questioned whether a novel class of 2,7-diarylsubstituted BDTs 1 (Figure 1) could be synthesized via a palladium-catalysed Suzuki-Miyaura reaction between heteroaryl halides 2 and organoboron derivatives 3 in Deep Eutectic Solvents (DESs), which have proven to be effective as sustainable and environmentally responsible reaction media in several transition-metal-catalyzed reactions [5].In this communication, we report our preliminary results on the preparation of diarylsubstituted BDTs 1, and discuss the substrate scope of the proposed protocol. Some of the compounds so far obtained display interesting photophysical properties, which are currently under investigation

Increased Urinary Angiotensin-Converting Enzyme 2 in Renal Transplant Patients with Diabetes

Angiotensin-converting enzyme 2 (ACE2) is expressed in the kidney and may be a renoprotective enzyme, since it converts angiotensin (Ang) II to Ang-(1-7). ACE2 has been detected in urine from patients with chronic kidney disease. We measured urinary ACE2 activity and protein levels in renal transplant patients (age 54 yrs, 65% male, 38% diabetes, n = 100) and healthy controls (age 45 yrs, 26% male, n = 50), and determined factors associated with elevated urinary ACE2 in the patients. Urine from transplant subjects was also assayed for ACE mRNA and protein. No subjects were taking inhibitors of the renin-angiotensin system. Urinary ACE2 levels were significantly higher in transplant patients compared to controls (p = 0.003 for ACE2 activity, and p≤0.001 for ACE2 protein by ELISA or western analysis). Transplant patients with diabetes mellitus had significantly increased urinary ACE2 activity and protein levels compared to non-diabetics (p<0.001), while ACE2 mRNA levels did not differ. Urinary ACE activity and protein were significantly increased in diabetic transplant subjects, while ACE mRNA levels did not differ from non-diabetic subjects. After adjusting for confounding variables, diabetes was significantly associated with urinary ACE2 activity (p = 0.003) and protein levels (p<0.001), while female gender was associated with urinary mRNA levels for both ACE2 and ACE. These data indicate that urinary ACE2 is increased in renal transplant recipients with diabetes, possibly due to increased shedding from tubular cells. Urinary ACE2 could be a marker of renal renin-angiotensin system activation in these patients

Ligand-Free Cobalt-Catalyzed Cross-Coupling Reaction Between Organoaluminum Reagents and (Hetero)Aryl and Alkyl Bromides

Transition-metal catalyzed cross-coupling reactions are some of the most important C−C bond-forming protocols and have been widely applied both in academic research and in industry. Since the discovery of cross-coupling reactions in the early 1970’s, a great number of catalytic systems using organoboron, organotin, organosilicon, organozinc or organozirconium, and organomagnesium as coupling reagents have been developed. In contrast, coupling reactions employing organoaluminum reagents are very rare. These reagents exhibited high chemoselectivity and good compatibility of functional groups in C−C bond formation reactions. Moreover, aluminum exhibits low toxicity and is one of the most inexpensive and earth-abundant metals. As part of our current research interest in developing new catalytic synthetic methodologies, in this communication we report a very general, cobalt catalyzed cross coupling reaction between alkyland aryl-aluminum compounds with alkyl- and (hetero)aryl bromides, affording the C(sp2)−C(sp2) and C(sp3)−C(sp2) cross-coupled products in good to excellent yields. Catalyzed by the cheap and commercially available CoCl2, without external ligands or bases, the reactions proceed smoothly with a wide range of substituted bromides, decorated by electrodonating and electro-withdrawing group, providing a versatile methodology for cobalt-mediated cross-coupling processes

Cobalt-catalyzed cross-coupling reactions of aryl- And alkylaluminum derivatives with (hetero)aryl and alkyl bromides

A simple cobalt complex, such as Co(phen)Cl2, turned out to be a highly efficient and cheap precatalyst for a host of cross-coupling reactions involving aromatic and aliphatic organoaluminum reagents with aryl, heteroaryl and alkyl bromides. New C(sp2)-C(sp2) and C(sp2)-C(sp3) bonds were formed in good to excellent yields and with high chemoselectivity, under mild reaction conditions

Factors influencing program selection among family practice residents

Factors on which family practice residents base their judgments about ranking programs are identified. Questionnaires were mailed to 1,810 first-year family practice residents who participated in the 1981 matching program; 830 (46 percent) responded. The questionnaire items were factor analyzed, and nine factors accounting for 59.4 percent of the variance emerged. Reliability for the questionnaire was estimated to be .82 using coefficient alpha. Factor scores for the nine subscales were computed and employed as dependent variables in several multivariate analyses of variance. Significant differences for sex, age, race, and geographical region were found on various factors; these findings indicated differences in what those groups considered important when selecting a residency

Synthesis of benzodithiophene systems by a ligand-free Suzuki-Miyaura coupling reaction in Deep Eutectic Solvents

Benzo[1,2-b:4,3-b\u2019]dithiophene (BDT) and its derivatives belong to an interesting class of thiophene-based aromatic \u3c0-conjugated compounds that are widely studied as functional organic materials inserted, for instance, as units in mono and polydisperse oligomers, or as \u3c0-spacers in push-pull organic chromophores for photovoltaic applications1. Moreover, BDTs are key intermediates for the synthesis of inherent chiral tetrathia[7]helicenes, which are an attractive class of heterohelicenes with unique physicochemical and chiroptical properties due to their helix-like structure2. Thus, BDT is a key starting molecule which can allow access to more complex and interesting systems through a selective and judicious functionalization of the \u3b1 and \u3b2-positions of the terminal thiophene rings. Building on our recent studies on the synthesis and functionalization of BDTs3, we questioned whether a novel class of 2,7-diarylsubstituted BDTs 1 (Figure 1) could be synthesized via a palladium-catalysed Suzuki-Miyaura reaction between heteroaryl halides 2 and organoboron derivatives 3 in Deep Eutectic Solvents (DESs), which have proven to be effective as sustainable and environmentally responsible reaction media in several transition-metal-catalyzed reactions4. In this communication, we report our preliminary results on the preparation of diarylsubstituted BDTs 1, and discuss the substrate scope of the proposed protocol. Some of the compounds so far obtained display interesting photophysical properties, which are currently under investigation

Directed ortho-metalation–nucleophilic acyl substitution strategies in deep eutectic solvents: the organolithium base dictates the chemoselectivity

Directed ortho metalation (DoM) or nucleophilic acyl substitution (SNAc) can be efficiently programmed on the same aromatic carboxylic acid amide, in a choline chloride-based eutectic mixture, by simply switching the nature of the organolithium reagent. Telescoped, one-pot ortho-lithiation/Suzuki-Miyaura cross-couplings have also been demonstrated for the first time in Deep Eutectic Solvents

Non-biodegradable polymers depolymerization in eco-friendly deep eutectic solvents

Synthetic polymeric materials like polyethylene terephthalate (PET), polyurethane (PU), polyethylene (PE) are widely used in all kinds of products in our day-to-day life, due to their low cost (compared to other materials), and for their unique properties, such as high chemical inertness and mechanical resistance. At the same time, however, most of them are almost completely non-biodegradable, and have been progressively accumulated in the environment. The so-called hard non-packaging plastic wastes and scraps, for example, if not correctly delivered/disposed, represent an environmental problem that does not seem to have adequate solutions yet. Chemical degradation processes of polymeric waste are more expensive than mechanical recycling, as they require high temperatures, high pressures or long times for a complete depolymerization, although a high-value quality of recycled monomer or other products can be obtained from these treatments. There is, therefore, a pressing need of greener technologies for the treatment and recycling of plastic wastes, and in particular for the upcycling of polymers derived from fossil hydrocarbons, such as PET, PU and PE wastes. In this communication, we present some preliminary results on the depolymerization of such materials (e.g. PET) in different eco-friendly Deep Eutectic Solvents (DESs) as reaction media, in combination with mechanical or physical treatments (e.g., sonication, microwave irradiation) or with basic or acidic green catalysts for a low-energy/impact degradation, and for the production of a new portfolio of products with high-added value, of which post-consumer waste can represent a new raw material