The CO bond of phenol can be activated by reaction with arylsulfonyl chlorides to yield the corresponding arylsulfonates that can be used as electrophilic partners in subsequent reactions. Arylsulfonates can be conveniently synthesized from inexpensive phenol derivatives and sulfonyl chlorides. Moreover, their crystalline nature makes arylsulfonates easier than other electrophiles to purify and store over a long period of time. Although arylsulfonates are inferior to triflates in terms of electrophilicity, triflates are better leaving groups compared to sulfonates; arylsulfonates however have greater economical advantages over triflates. Facile synthesis of different arylsulfonates from various arylsulfonyl chlorides and phenol are reported. What is unique about the synthesis is that very good to excellent yields of arylsulfonates were obtained without the use of column chromatography. A more efficient purification technique was developed based on recrystallization. Using 2,4-dinitrophenyl 4-methylbenzenesulfonate and various amines, initial experiments have shown greater regioselectivity for the S N Ar products.
Objectives Abdominal aortic aneurysms (AAAs) demonstrating hostile neck anatomy (HNA) are associated with increased perioperative risk and mortality. A number of these patients are not suitable for standard endovascular aneurysm repair (EVAR) and are high risk for open surgery. We present our experience with the first implantations in Scotland of a novel conformable aortic stent-graft designed to overcome some of the challenges of HNAs. Methods From May 2018 to March 2022, 24 consecutive patients with non-ruptured AAAs demonstrating HNAs (neck length < 15 mm, or angulation > 60°) were treated with GORE Excluder Conformable AAA endoprosthesis (CLEVAR) (CEXC Device, W.L. Gore and Associates, Flagstaff, AZ, USA) at a Scottish vascular centre. We assessed clinical outcomes and technical success of CLEVAR during deployment, primary admission and the post-operative period at 3- and 12-month clinical follow-up alongside CT angiography. Results Twenty-four patients (20 males, mean age 75.6) were included. Primary technical success of proximal seal zones and CLEVAR deployment (no type 1/3 endoleaks, no conversion to open repair, AAA excluded and patient leaving theatre alive) was achieved in 100% of patients. All patients were alive and clinically stable at 3- and 12-month follow-up. There were five patients requiring re-intervention; at the 3-month follow-up, one patient (4.2%) developed a type 1b endoleak requiring graft limb extension, one patient developed a right common femoral artery dissection requiring open repair and one patient required a limb extension of the right iliac limb due to risk of developing a type 1b endoleak. At the 12-month follow-up, two patients required embolization of type 2 endoleaks and no patients demonstrated type 1 or type 3 endoleaks. Conclusions: In-hospital and post-operative 3- and 12-month clinical and angiographic outcomes demonstrate safety and efficacy with CLEVARs in treating unruptured AAAs with HNA. Further research involving larger heterogenous sample sizes is warranted to determine long-term clinical outcomes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.