The cadmium(II) chloride-catalyzed dehydrative CÀP cross-coupling reaction of propargyl alcohols with diarylphosphine oxides is reported. Several propargyl alcohols including those bearing the sterically demanding tert-butyl group at the triple bond terminus can be used as good substrates in the reaction to produce the corresponding allenylphosphine oxides in good to high yields in acetonitrile at 100 8C. The reaction can also be easily scaled up to a gram-scale synthesis. A mechanism study indicates that the reaction may proceed through a process of propargylic substitution to generate phosphonite intermediates followed by [2,3] sigmatropic rearrangement to produce the allenyl products, rather than through a common allenylative substitution resulting from Pnucleophilicity. Scheme 4. (a) Tautomeric equilibrium between 2 and 2'; (b) The proposed mechanism.UPDATES
Background The association between the type of anesthesia used and the recurrence of cancer remains controversial. This study aimed to compare the effects of local vs general anesthesia on recurrence-free survival and cost after breast-conserving surgery. Materials and Methods We reviewed the data of 2778 patients who underwent breast-conserving surgery followed by radiation at our center between 1999 and 2014. We analyzed the data of 994 patients with hormone receptor-positive and Her2-negative tumors who underwent breast-conserving surgery without axillary lymph node dissection under local or general anesthesia. Patients were grouped according to whether local or general anesthesia was used for the surgery. Results Of the 994 patients enrolled in this study, 367 received local anesthesia and 627 patients received general anesthesia. The median follow-up duration for all patients was 93 months. The Kaplan–Meier survival curves did not reveal significant differences between the recurrence-free survival of the two groups, with 5-year recurrence-free survival rates of 96.3% (95% CI, 94.3–98.3%) in the local anesthesia group and 97.3% (95% CI, 95.9–98.7%) in the general anesthesia group. The total cost of hospitalization in the local anesthesia group was significantly lower than that in the general anesthesia group ( P <.001). The difference in the cost between the two groups remained significant, irrespective of the type of hospitalization, after excluding 165 patients receiving chemotherapy during their hospitalization. Conclusions Our analysis indicated no association between the type of anesthesia used during breast-conserving surgery and the long-term prognosis of breast cancer. However, breast-conserving surgery under local anesthesia may be a less expensive option than that under general anesthesia.
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.