Palladium‐Catalyzed Formal Hydroalkylation of Aryl‐Substituted Alkynes with Hydrazones
作者:Lin Yu、Leiyang Lv、Zihang Qiu、Zhangpei Chen、Ze Tan、Yu‐Feng Liang、Chao‐Jun Li
DOI:10.1002/anie.202005132
日期:2020.8.10
naturally abundant aldehydes, as both alkylation reagents and hydrogen donors. The hydroalkylation proceeds with high regio‐ and stereoselectivity to form (Z )‐alkenes, which are more difficult to generate compared to (E )‐alkenes. The reaction is compatible with a wide range of functional groups, including hydroxy, ester, ketone, nitrile, boronicester, amine, and halide groups. Furthermore, late‐stage modifications
Switch in Selectivity for Formal Hydroalkylation of 1,3‐Dienes and Enynes with Simple Hydrazones
作者:Leiyang Lv、Lin Yu、Zihang Qiu、Chao‐Jun Li
DOI:10.1002/anie.201915875
日期:2020.4.16
anti-Markovnikov addition is obtained by changing to a ruthenium catalyst, thus providing direct and efficient access to homoallylic products exclusively. Isotopic substitution experiments indicate that no reversible hydro-metallation across the metal-π-allyl system occurred under ruthenium catalysis. Moreover, this protocol is applicable to the regiospecific hydroalkylation of the distal C=C bond of 1,3-enynes
Nickel-catalyzed alkyl–alkyl cross-coupling reactions of non-activated secondary alkyl bromides with aldehydes as alkyl carbanion equivalents
作者:Chenghao Zhu、Junliang Zhang
DOI:10.1039/c9cc00307j
日期:——
A novel nickel-catalyzed alkyl–alkyl cross coupling of non-activatedsecondaryalkylbromides with aldehydes via hydrazone intermediates has been developed. Aldehydes as alkyl carbanion equivalents replace traditional organometallic reagents. This coupling occurs on the carbon of the hydrazone rather than the nitrogen. In addition, non-activated primary and tertiary alkylbromides also undergo the
Palladium‐Catalyzed Defluorinative Alkylation of
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‐Difluorocyclopropanes: Switching Regioselectivity via Simple Hydrazones
作者:Leiyang Lv、Chao‐Jun Li
DOI:10.1002/anie.202102240
日期:2021.6
can completely switch the reaction selectivity to give the alkylated α-fluoroalkene skeletons (branched selectivity). The unique reactivity of hydrazones that enables analogous inner-sphere 3,3′-reductive elimination driven by denitrogenation, as well as the assistance of steric-embedded N-heterocyclic carbene ligand, are the key to switch the regioselectivity. A wide range of hydrazones derived from