Ni<sup>I</sup>Catalyzes the Regioselective Cross-Coupling of Alkylzinc Halides and Propargyl Bromides to Allenes
作者:Rita Soler-Yanes、Iván Arribas-Álvarez、Manuel Guisán-Ceinos、Elena Buñuel、Diego J. Cárdenas
DOI:10.1002/chem.201603758
日期:2017.1.31
We describe the unprecedented formation of allenes by Ni‐catalyzed cross‐coupling of propargyl bromides with alkylzinc halides. The reaction regioselectivity is complementary to the previously reported formation of propargyl‐coupled compounds. Experiments support the formation of NiI complexes as the active species and the participation of radical intermediates. Kinetic studies showed that the reaction
<i>trans</i>
‐Hydroboration of Propargyl Alcohol Derivatives and Related Substrates
作者:Lauren E. Longobardi、Alois Fürstner
DOI:10.1002/chem.201902228
日期:2019.8
in good to excellent levels of regio‐ as well as stereoselectivity, provided that the triple bond bears one linear and one singly‐branched substituent. In such cases, the reaction follows an unusual trans‐addition mode and places the boron entity distal to the branching point. The resulting alkenyl boronates, which are difficult to make otherwise, can be engaged in numerous enabling downstream processes
Hydroxyl-Assisted Carbonylation of Alkenyltin Derivatives: Development and Application to a Formal Synthesis of Tubelactomicin A
作者:Heiko Sommer、Alois Fürstner
DOI:10.1021/acs.orglett.6b01431
日期:2016.7.1
Alkenyltin derivatives flanked by a hydroxylgroup are subject to methoxycarbonylation when treated with catalytic amounts of Pd(OAc)2 and Ph3As in MeOH under a CO atmosphere; key to success is the use of 1,4-benzoquinone as a stoichiometric oxidant in combination with trifluoroaceticacid as a cocatalyst. The acid lowers the LUMO of the quinone and likely marshals the critical assembly of the substrates
We found that the combination of [Ir(cod)Cl]2 and rac-BINAP served as an efficient catalyst for the [2+2+2] cycloaddition of 2,7-nonadiyne derivatives and related compounds with alkynyl ketones and alkynyl esters. The corresponding products were obtained in high yields under mild reaction conditions.
Iron-Catalyzed Coupling of Propargyl Bromides and Alkyl Grignard Reagents
作者:Pablo Domingo-Legarda、Rita Soler-Yanes、M. Teresa Quirós-López、Elena Buñuel、Diego J. Cárdenas
DOI:10.1002/ejoc.201800849
日期:2018.9.23
An iron‐catalyzed cross‐coupling reaction of propargyl bromides with alkylmagnesium reagents affords either allene‐ or propargyl‐coupled products in smooth conditions, and tolerates the presence of functional groups.