A Substrate-Driven Approach to Determine Reactivities of α,β-Unsaturated Carboxylic Esters Towards Asymmetric Bioreduction
作者:Gábor Tasnádi、Christoph K. Winkler、Dorina Clay、Nargis Sultana、Walter M. F. Fabian、Mélanie Hall、Klaus Ditrich、Kurt Faber
DOI:10.1002/chem.201200990
日期:2012.8.13
The degree of CC bond activation in the asymmetricbioreduction of α,β‐unsaturated carboxylicesters by ene‐reductases was studied, and general recommendations to render these “borderline‐substrates” more reactivetowards enzymatic reduction are proposed. The concept of “supported substrate activation” was developed. In general, an additional α‐halogenated substituent proved to be beneficial for enzymatic
An expedient synthesis of N-unsubstituted 1,2,3-triazole-4-carboxylates has been demonstrated through [3 + 2] cycloaddition of sodium azide with α-haloacrylates. The process is highly reliable and exhibits an unusually wide scope with respect to α-fluoro-, α-chloro-, α-bromo-, and α-iodoacrylates. The potential of selected 1,2,3-triazole-4-carboxylates in the preparation of 1,5-dihydro-4H-[1,2,3]-triazolo-[4,5-c]-quinolin-4-one has also been illustrated.
Exploring the reaction of iodine with<i>α</i>-diazo esters
作者:Giancarlo Verardo、Paola Geatti、Alberto Gambi
DOI:10.1002/poc.1420
日期:2009.1
In this paper we describe the unprecedented reaction between α‐diazoesters 1 and iodine. The reaction, carried out in the presence of aqueous NaHCO3, afforded the Z‐isomer of the corresponding unsaturated‐2‐iodo ester 8. The configuration of compounds 8 was determined using the 3JCH coupling between carbonyl carbon atom and alkene proton. Mechanistic considerations accounting for the observed phenomena
α-Iodo-α,β-Unsaturated Ketones as Vicinal Dielectrophiles: Their Reactions with Dinucleophiles Provide New Annulation Protocols for the Formation of Carbo- and Heterocyclic Ring Systems
作者:Yu Chen、Michael G. Gardiner、Ping Lan、Martin G. Banwell
DOI:10.1021/acs.joc.2c00383
日期:2022.5.6
α-Iodo-α,β-unsaturated ketones such as compound 1 serve as vicinal dielectrophiles and react with a range of dinucleophiles including pentane-2,4-dione and 1,3-indandione to produce [3 + 2]- and [2 + 1]-adducts such as 5 and 38, respectively. [4 + 2]- and [5 + 2]-cycloadducts have been obtained from compound 1 by related means. Preliminary studies reveal that α-iodinated α,β-unsaturated esters can