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.
Dioxygen mediated hydroacylation of vinyl sulfonates and sulfones on water
作者:Vijay Chudasama、Richard J. Fitzmaurice、Jenna M. Ahern、Stephen Caddick
DOI:10.1039/b914563j
日期:——
Herein we report a mild, facile method for the preparation of 1,4-keto-sulfonates and sulfones on water. Further synthetic manipulations can result in products that are not readily accessed by hydroacylation of electron rich alkenes.
Gold- and Silver-Catalyzed Reactions of Propargylic Alcohols in the Presence of Protic Additives
作者:Matthew N. Pennell、Peter G. Turner、Tom D. Sheppard
DOI:10.1002/chem.201102830
日期:2012.4.10
secondary and tertiary propargylicalcohols undergo a Meyer–Schusterrearrangement to give enones at room temperature in the presence of a gold(I) catalyst and small quantities of MeOH or 4‐methoxyphenylboronic acid. The syntheses of the enone natural products isoegomaketone and daphenone were achieved using this reaction as the key step. The rearrangement of primary propargylicalcohols can readily be combined