Metal-free, hydroacylation of CC and NN bonds via aerobic C–H activation of aldehydes, and reaction of the products thereof
作者:Vijay Chudasama、Ahmed R. Akhbar、Karim A. Bahou、Richard J. Fitzmaurice、Stephen Caddick
DOI:10.1039/c3ob41632a
日期:——
In this report, a thorough evaluation of the use of aerobically initiated, metal-free hydroacylation of various CC and NN acceptor molecules with a wide range of aldehydes is presented. The aerobic-activation conditions that have been developed are in sharp contrast to previous conditions for hydroacylation, which tend to use transition metals, peroxides that require thermal or photochemical degradation, or N-heterocyclic carbenes. The mildness of the conditions enables a number of reactions involving sensitive reaction partners and, perhaps most significantly, allows for α-functionalised chiral aldehydes to undergo radical-based hydroacylation with complete retention of optical purity. We also demonstrate how the resulting hydroacylation products can be transformed into other useful intermediates, such as γ-keto-sulfonamides, sultams, sultones, cyclic N-sulfonyl imines and amides.
Primary, secondary, and tertiary alkyl radicals formed by the photocatalyzed oxidation of organosilicates underwent efficient carbonylation with carbon monoxide (CO) to give a variety of unsymmetrical ketones. This study introduces the possibility of radical carbonylation under a photooxidative regime.
Hydroacylation of α,β-unsaturated esters via aerobic C–H activation
作者:Vijay Chudasama、Richard J. Fitzmaurice、Stephen Caddick
DOI:10.1038/nchem.685
日期:2010.7
using selectiveC–Hactivation as a direct route for generating reactive intermediates. In this article, we describe the use of aldehyde auto-oxidation as a simple, clean and effective method for C–Hactivation, resulting in the generation of an acyl radical. This acyl radical can be used for carbon–carbon bond formation and herein we describe the application of this method for the hydroacylation of α
Metal-Free CH Bond Activation of Branched Aldehydes with a Hypervalent Iodine(III) Catalyst under Visible-Light Photolysis: Successful Trapping with Electron-Deficient Olefins
作者:Shin A. Moteki、Asuka Usui、Sermadurai Selvakumar、Tiexin Zhang、Keiji Maruoka
DOI:10.1002/anie.201406513
日期:2014.10.6
of a hypervalentiodine(III) catalystunder visible light photolysis allows a mild way of generating acyl radicals from various branchedaldehydes, thereby giving the corresponding hydroacylated products almost exclusively. Another characteristic feature of this approach is the catalytic use of hypervalentiodine(III) reagent, which is a rare example on the generation of radicals in hypervalent iodine
Hypervalent iodine(III) catalyzed radical hydroacylation of chiral alkylidenemalonates with aliphatic aldehydes under photolysis
作者:Sermadurai Selvakumar、Qi-Kai Kang、Natarajan Arumugam、Abdulrahman I. Almansour、Raju Suresh Kumar、Keiji Maruoka
DOI:10.1016/j.tet.2017.08.018
日期:2017.10
bearing (−)-8-phenylmenthol as a chiral auxiliary with aliphaticaldehydes is realized under photolysis. This work represent the first example of diastereoselective addition of acyl radicals to olefins to afford chiral ketones in a highly stereoselective fashion. The reaction is initiated by the photolysis of hypervalent iodine(III) catalyst under mild and metal-free conditions. The synthetic potential