Monday, October 28, 2013
Tristan H. Lambert
Functional Group Interconversion
David Milstein at the Weizmann Institute of Science reported (Angew. Chem. Int. Ed. 2013, 52, 6269. ) the unusual deamination of amine 1 to alcohol 3 catalyzed by ruthenium complex 2. In the reverse sense, Qing Xu at Wenzhou University found (Adv. Synth. Catal. 2013, 355, 73. ) that the conversion of benzyl alcohol (4) to sulfonamide 5 was catalyzed by benzaldehyde and catalytic potassium carbonate.
Gold(I)-catalysis was utilized (Chem. Commun. 2013, 49, 4262. ) by Ai-Lan Lee at Heriot-Watt University for the direct etherification of allylic alcohol 6 with isopropanol to produce 7. Tobias Ritter at Harvard demonstrated (J. Am. Chem. Soc. 2013, 135, 2470. ) that the reagent PhenoFluor (9) developed in his lab displays astonishing selectivity for the late-stage deoxyfluorination of complex alcohols and polyols, including glucopyranoside 8 to produce 10.
A Mitsunobu protocol for the conversion of alcohol 11 to ester 13 using catalytic amounts of the hydrazide 12 and iron(II) phthalocyanine was developed (Angew. Chem. Int. Ed. 2013, 52, 4613. ) by Tsuyoshi Taniguchi at Kanazawa University. We reported (Org. Lett. 2013, 15, 38. ) a Mitsunobu-like inversion of alcohol 14 to mesylate 16 catalyzed by diphenylcyclopropenone 15.
Domingo Gomez Pardo and Janine Cossy at ESPCI Paris Tech found (Org. Lett. 2013, 15, 902. ) that the reagent XtalFluor-E (18) was effective for the coupling of N-Boc proline (17) and phenylglycine ethyl ester (19) without epimerization to furnish the dipeptide 20. The conversion of primary amide 21 to secondary amide 23 via cross-coupling with boronic acid 22 was reported (Org. Lett. 2013, 15, 2314. ) by Donald A. Watson at the University of Delaware.
Catalysis of the Lossen rearrangement of hydroxamide 24 to carbamate 26 using N-methylimidazole (25), which helped to minimize side products, was reported (Org. Lett. 2013, 15, 602. ) by Scott J. Miller at Yale University. Keiji Maruoka at Kyoto University demonstrated (Angew. Chem. Int. Ed. 2013, 52, 5532. ) that propionaldehyde (27) could be converted under simple conditions to N-Boc aminal 28, which served as a convenient source for the in situ generation of the corresponding highly useful N-Boc imine.
A convenient method for the conversion of alcohol 29 to nitrile 30 via dehydrogenative catalysis in the presence of ammonia was reported (Org. Lett. 2013, 15, 1850. ) by Yong Huang at Peking University. An exceptionally novel synthesis of nitrile 32 via the silver-catalyzed nitrogenation of alkyne 31 was developed (Angew. Chem. Int. Ed. 2013, 52, 6677. ) by Ning Jiao at Peking University.
A simple procedure for the conversion of unsaturated carboxylic acid 33 to nitrostyrene 34 using t-butylnitrite in the presence of TEMPO and air was disclosed (Chem. Commun. 2013, 49, 5286. ) by Debabrata Maiti at the Indian Institute of Technology Bombay. Finally, silver-catalyzed decarboxylative fluorination was achieved (Org. Lett. 2013, 15, 2648. ) in the conversion of difluoroacid 35 to trifluoromethylanisole 37 by the team of Sajinder K. Luthra at GE Healthcare at Amersham, Jan Passchier at Imanova, Ltd, Olof Solin at the University of Turku and Åbo Akademi University, and Véronique Gouverneur at the University of Oxford.
T. H. Lambert, Org. Chem. Highlights 2013, October 28.