<i>o</i>-Iodoxybenzoic Acid (IBX) as a Viable Reagent in the Manipulation of Nitrogen- and Sulfur-Containing Substrates: Scope, Generality, and Mechanism of IBX-Mediated Amine Oxidations and Dithiane Deprotections
作者:K. C. Nicolaou、Casey J. N. Mathison、Tamsyn Montagnon
DOI:10.1021/ja0400382
日期:2004.4.28
o-Iodoxybenzoic acid (IBX), a highly versatile hypervalent iodine(V) reagent, was found to efficiently mediate the dehydrogenation of amines in addition to facilitating the oxidative cleavage of dithioacetals and dithioketals. Through the development of relevant IBX-based protocols, a plethora of useful synthetic intermediates, including imines, oximes, ketones, and aromatic N-heterocycles, were found
A Pd‐catalyzed carbonylation of α‐chloro ketones in the presence of imines leads to α‐alkylidene β‐oxo amides in good yields. This one‐pot synthetic method is highly stereoselective and affords amides only as (Z) isomers. This work increases the potential of Pd‐catalyzed reactions in the direct synthesis of carbonyl compounds.
Origin of the Relative Stereoselectivity of the β-Lactam Formation in the Staudinger Reaction
作者:Lei Jiao、Yong Liang、Jiaxi Xu
DOI:10.1021/ja056711k
日期:2006.5.1
stereoselectivity of the beta-lactam formation is one of the critical issues in the Staudinger reaction. Although many attempts have been made to explain and to predict the stereochemical outcomes, the origin of the stereoselectivity remains obscure. We are proposing a model that explains the relative stereoselectivity based on a kinetic analysis of the cis/trans ratios of reaction products. The results were
Allylic Oxidations Catalyzed by Dirhodium Catalysts under Aqueous Conditions
申请人:Doyle Michael P.
公开号:US20090093638A1
公开(公告)日:2009-04-09
The present invention relates to compositions and methods for achieving the efficient allylic oxidation of organic molecules, especially olefins and steroids, under aqueous conditions. The invention concerns the use of dirhodium (II,II) “paddlewheel complexes, and in particular, dirhodium carboximate and tert-butyl hydroperoxide as catalysts for the reaction. The use of aqueous conditions is particularly advantageous in the allylic oxidation of 7-keto steroids, which could not be effectively oxidized using anhydrous methods, and in extending allylic oxidation to enamides and enol ethers.
Exploring SmBr2-, SmI2-, and YbI2-Mediated Reactions Assisted by Microwave Irradiation
作者:Anders Dahlén、Edamana Prasad、Robert A. Flowers、Göran Hilmersson
DOI:10.1002/chem.200401320
日期:2005.5.20
hexamethyl phosphoramide (HMPA). The redox potential of YbI2 in tetrahydrofuran (THF) has been determined as -1.02+/-0.05 V (versus Ag/AgNO3) by cyclic voltammetry. A large selectivity difference in various reactions was observed depending on the redox potential of the LnX2 reagent. The morepowerful reductant, SmBr2, afforded mainly pinacol-coupling products of ketones whereas the weaker reductant YbI2 afforded