PhIO as a Powerful Cyclizing Reagent: Regiospecific [3+2]-Tandem Oxidative Cyclization of Imine toward Cofacially Self-Aggregated Low Molecular Mass Organic Materials
作者:Palash Pandit、Nirbhik Chatterjee、Samiran Halder、Sandip K. Hota、Amarendra Patra、Dilip K. Maiti
DOI:10.1021/jo8028136
日期:2009.3.20
The powerful cyclization and tandem oxidation property of environmentallybenign PhIO is developed for the first time, which leads to regiospecific [3+2]-tandem oxidative cyclization of imine at room temperature in rapid access to a new class of compounds, 1,2-functionalized 4,5-diarylimidazoles, in excellent yield with synthetic efficiency. Size, shape, and activity of the involved nanoreactors for
Sequential Reduction of Nitroalkanes Mediated by CS<sub>2</sub> and Amidine/Guanidine Bases: A Controllable Nef Reaction
作者:Minsoo Ju、Weiyang Guan、Jennifer M. Schomaker、Kaid C. Harper
DOI:10.1021/acs.orglett.9b02987
日期:2019.11.15
In this letter, we describe a mild, functional group-tolerant reductive Nef reaction that utilizes CS2 and an amidine or guanidine base to sequentially cleave N–O bonds. These conditions transform secondary nitroalkanes to ketones via an isolable oxime with minimal erosion at labile stereogenic carbons, show excellent compatibility with groups sensitive to oxidizing or reducing conditions, display
Stereospecific Synthesis of Pyrrolidines with Varied Configurations via 1,3-Dipolar Cycloadditions to Sugar-Derived Enones
作者:Guillermo A. Oliveira Udry、Evangelina Repetto、Oscar Varela
DOI:10.1021/jo500547y
日期:2014.6.6
Enantiomerically pure pyrrolidines have been obtained by 1,3-dipolarcycloaddition of stabilized azomethine ylides and sugar enones (dihydropyranones) derived from pentoses. Thus, the S-enone (menthyl 3,4-dideoxy-(1S)-pent-3-enopyranosid-2-ulose) was prepared from d-xylose, while the R analogue was obtained from l-arabinose. The dipoles were generated in situfrom α-arylimino esters of common aminoacids (glycine