- Chemoselective Schwartz Reagent Mediated Reduction of Isocyanates to Formamides
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Addition of the in situ generated Schwartz reagent to widely available isocyanates constitutes a chemoselective, high-yielding, and versatile approach to the synthesis of variously functionalized formamides. Steric and electronic factors or the presence of sensitive functionalities (esters, nitro groups, nitriles, alkenes) do not compromise the potential of the method. Full preservation of the stereochemical information contained in the starting materials is observed. The use of formamides in the nucleophilic addition of organometallic reagents (Chida-Sato allylation, Charette-Huang addition to imidoyl triflate activated amides, Matteson homologation of boronic esters) is briefly investigated.
- Pace, Vittorio,De La Vega-Hernández, Karen,Urban, Ernst,Langer, Thierry
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supporting information
p. 2750 - 2753
(2016/06/15)
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- Synthesis and stability study of isocyano aryl boronate esters and their synthetic applications
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A facile synthesis of isocyano arylboronate esters is reported. Although tri-coordinate boron functional groups are commonly recognized as vulnerable to nucleophilic attack, the newly reported tri-coordinate isocyano arylboronate esters were found to be stable, albeit owing to the presence of an isocyano group. Theoretical calculations, using the DFT/B3LYP/6-31G(d,p) method, revealed that the electron delocalization between the aryl group and the boron atom might contribute to this stability. UV-vis spectroscopic investigations on 2-(4-isocyanophenyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane (2a) were in agreement with the theoretical studies, showing a red-shifted absorption compared with that of phenylisonitrile. The reported strategy allows boronate ester substrates to survive throughout two-step operations. Two of the compounds synthesized were successfully exploited in Ugi and Passerini multicomponent reactions to afford corresponding products. In addition, two boron-containing tetrazoles were also prepared under environmentally benign conditions. These results demonstrated that functionalized isocyanides are stable and can be used as strategically as synthetic building blocks.
- Fang, Hao-Ping,Fu, Chia-Chieh,Tai, Chin-Kuen,Chang, Ken-Hao,Yang, Ru-Han,Wu, Meng-Ju,Chen, Hsien-Chi,Li, Chia-Jung,Huang, Shi-Qing,Lien, Wan-Hsiang,Chen, Chih-Hsin,Hsieh, Chung-Hung,Wang, Bo-Cheng,Cheung, Siu-Fung,Pan, Po-Shen
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p. 30362 - 30371
(2019/01/08)
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- NOVEL BIPHENYL COMPOUNDS AND THEIR USE
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The invention is directed to certain biphenyl compounds. Specifically, the invention is directed to compounds according to Formula (I): wherein R1, R2, R3, R4, R5, R6, R7, R8, R9, and Y are as defined below, and to pharmaceutically-acceptable salts thereo
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Page/Page column 49
(2010/10/20)
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