Efficient C-C bond cleavage is recognized as a persistent challenge in the field of synthetic methodology. In this study, we found that tertiary alkyl radicals are smoothly formed from tertiary alkylated dienones (BHT adducts) via SET, using PDI as a photocatalyst. Resulting tert-alkyl radicals could be applied to the tert-alkylation of enamides. The driving force of this C-C bond cleavage reaction is the mesolytic cleavage of the BHT adducts. The mechanistic study revealed that PDI anion radical is the key active species during the catalytic cycle.
PURPOSE: This study proposes a detection support system for primary and metastatic lesions of prostate cancer using 18 F -PSMA 1007 positron emission tomography/computed tomography (PET/CT) images with non-image information, including patient metadata and location information of an input slice image. METHODS: A convolutional neural network with condition generators and feature-wise linear modulation (FiLM) layers was employed to allow input of not only PET/CT images but also non-image information, namely, Gleason score, flag of pre- or post-prostatectomy, and normalized z-coordinate of an input slice. We explored the insertion position of the FiLM layers to optimize the conditioning of the network using non-image information. RESULTS: 18 F -PSMA 1007 PET/CT images were collected from 163 patients with prostate cancer and applied to the proposed system in a threefold cross-validation manner to evaluate the performance. The proposed system achieved a Dice score of 0.5732 (per case) and sensitivity of 0.8200 (per lesion), which are 3.87 and 4.16 points higher than the network without non-image information. CONCLUSION: This study demonstrated the effectiveness of the use of non-image information, including metadata of the patient and location information of the input slice image, in the detection of prostate cancer from 18 F -PSMA 1007 PET/CT images. Improvement in the sensitivity of inactive and small lesions remains a future challenge.
Positron Emission Tomography Computed Tomography , Prostatic Neoplasms , Male , Humans , Positron Emission Tomography Computed Tomography/methods , Prostatic Neoplasms/diagnostic imaging , Prostatic Neoplasms/surgery , Prostatic Neoplasms/pathology , Prostatectomy
In this study, we found that the sterically bulky α-hydroxycarboxamide moiety is a suitable framework for protecting the boronyl group of boron reagents during aminations. Condensation of α-hydroxycarboxamide with ArB(OH)2 produced aryloxazaborolidinone (ArOxB). The reactivity of the C-B bond in ArOxB is easily controlled by the steric and weak electronic effects of the backbone. H2N-(or Br-)ArOxB underwent Chan-Evans-Lam (C-E-L) or Buchwald-Hartwig (B-H) amination with retaining the C-B bond. On the other hand, direct C-E-L amination of ArOxB was also possible in an oxidative atmosphere, in which the C-B bond was activated by CuII species. Our methodology is effective for the precise synthesis of two or more arylamino group substituted arenes.
It was demonstrated that α-hydroxycarboxamide is an excellent boron-protecting group. The reaction between α-hydroxycarboxamide and organoboronic acids produced stable oxazaborolidinones (OxBs), in which the sp 2 ${{_{{\rm sp}{^{2}}}}}$ -hybridized boron atom was sterically protected by α-hydroxycarboxamide. The alkyl groups of the α-hydroxycarboxamide moiety can dynamically cover the p-orbital of the sp 2 ${{_{{\rm sp}{^{2}}}}}$ -hybridized boron center, creating a small space around the boron atom, allowing for smooth transmetalation by a Pd catalyst and easy deprotection by water. This protecting phenomenon is effective for readily purification, Suzuki-Miyaura coupling reactions with unstable boronic acids and iterative cross-couplings.
Although extracorporeal membrane oxygenation is relatively contraindicated in patients with severe disseminated intravascular coagulation (DIC), it can be safely introduced by providing adequate anti-DIC therapy.
Herein, we report a copper-catalyzed stereospecific fluorination involving CsF and α-bromocarboxamides as tertiary alkyl sources that, unlike traditional stereospecific routes involving stereoinversive SN 2 reactions, proceeds with retention of stereochemistry. The developed stereospecific Cu-catalyzed reaction is among the most efficient methods for synthesizing fluorinated molecules that possess highly congested stereogenic carbon centers. Mechanistic studies revealed that the combined reactivity of CuF2 and Cs salt is essential for completing the catalytic cycle. Our catalytic system underwent fluorination exclusively with tertiary alkyl bromides and did not react with primary alkyl bromides, indicating that this stereospecific fluorination methodology is suitable for synthesizing fluorinated building blocks possessing stereo-defined F-containing tertiary carbon stereogenic center.
