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.
Functionalisation of aldehydes via aerobic hydroacylation of azodicarboxylates ‘on’ water
作者:Vijay Chudasama、Jenna M. Ahern、Dipti V. Dhokia、Richard J. Fitzmaurice、Stephen Caddick
DOI:10.1039/c0cc04520a
日期:——
Herein we report the functionalisation of aldehydesvia hydroacylation of azodicarboxylates. A range of functionalised aldehydes are employed as the limiting reagent including chiral non-racemic aldehydes bearing α-stereocentres which are functionalised giving access to enantiomerically pure products. The resultant hydrazides can be employed as acyl donors in the synthesis of amides.
Enabling the facile conversion of acyl hydrazides into N-acyl carbamates via metal-free ionic-based rupture of the N–N linkage
作者:André Shamsabadi、Jack Ren、Vijay Chudasama
DOI:10.1039/c7ra04178k
日期:——
the one-pot transformation of readily synthesised/easily accessed acyl hydrazides into N-acyl carbamatesvia an alkylation-elimination reaction sequence. A range of N-acyl carbamates are prepared in consistent yields, including those featuring protectinggroups and having alkyl & aryl N-acyl functionality. The reaction conditions also tolerate a wide variety of sensitive functional groups.
A facile route to 1<i>H</i>- and 2<i>H</i>-indazoles from readily accessible acyl hydrazides by exploiting a novel aryne-based molecular rearrangement
作者:André Shamsabadi、Vijay Chudasama
DOI:10.1039/c8cc06556j
日期:——
A facile procedure for the conversion of readily accessible acyl hydrazides into 1H and 2H-indazoles via a novel aryne-based molecular rearrangement pathway.
一种简便的将易得的酰基肼转化为1H和2H-吲唑的程序,通过一种基于新颖芳炔的分子重排途径。
A new facile pyridine-catalyzed hydroacylation of aldehydes with azodicarboxylates under microwave irradiation
An efficient metal free hydroacylation of aromatic aldehydes with azadicarboxylate has been developed using pyridine as a catalyst providing an easy access for hydroacylation products in good yields. (C) 2014 Elsevier Ltd. All rights reserved.