Development of Enantiospecific Coupling of Secondary and Tertiary Boronic Esters with Aromatic Compounds
作者:Marcin Odachowski、Amadeu Bonet、Stephanie Essafi、Philip Conti-Ramsden、Jeremy N. Harvey、Daniele Leonori、Varinder K. Aggarwal
DOI:10.1021/jacs.6b03963
日期:2016.8.3
functional groups (esters, azides, nitriles, alcohols, and ethers). The reaction also worked well with other electron-rich heteroaromatics and 6-membered ring aromatics provided they had donor groups in the meta position. Conditions were also found under which the B(pin)- moiety could be retained in the product, ortho to the boron substituent. This protocol, which created a new C(sp2)–C(sp3) and an adjacent
Chiral Aniline Synthesis via Stereospecific C(sp<sup>3</sup>)–C(sp<sup>2</sup>) Coupling of Boronic Esters with Aryl Hydrazines
作者:Venkataraman Ganesh、Adam Noble、Varinder K. Aggarwal
DOI:10.1021/acs.orglett.8b02615
日期:2018.10.5
is promoted by acylation of a hydrazinyl arylboronate complex, which triggers a N-N bond cleavage with concomitant 1,2-metalate rearrangement. Judicious choice of the acylating agent enabled the synthesis of ortho- and para-substituted anilines with essentially complete enantiospecificity from a wide range of boronic ester substrates.
描述了烷基硼酸酯和锂化芳基肼之间的对映体特异性偶联。该反应在无过渡金属条件下进行,并通过肼基芳基硼酸盐络合物的酰化促进,从而引发 NN 键断裂并伴随 1,2-金属酸盐重排。酰化剂的明智选择使得能够从广泛的硼酸酯底物合成具有基本完全对映专一性的邻位和对位取代的苯胺。
Synthesis of Highly Enantioenriched C-Tertiary Amines From Boronic Esters: Application to the Synthesis of Igmesine
作者:Viktor Bagutski、Tim G. Elford、Varinder K. Aggarwal
DOI:10.1002/anie.201006037
日期:2011.2.1
Better than all the rest: Tertiaryboronicesters, readily available using the lithiation–borylation reaction, have been converted into tertiary alkylamines in very high ee. The work has been applied to a short, modular, and fully stereocontrolled synthesis of the pharmaceutical igmesine and chiral 2,2‐disubstituted piperidines.
Synthesis of Functionalized Alkenes by a Transition-Metal-Free Zweifel Coupling
作者:Roly J. Armstrong、Worawat Niwetmarin、Varinder K. Aggarwal
DOI:10.1021/acs.orglett.7b01124
日期:2017.5.19
a powerful method for the synthesis of alkenes, serving as a transition-metal-free alternative to the Suzuki–Miyaura reaction. To date, the scope of the Zweifel coupling has been rather narrow and has focused mainly on the coupling of vinyllithium reagents to synthesize simple aryl- and alkyl-substituted olefins. Herein, the development of a general transition-metal-free coupling process enabling the
Ate Complexes of Secondary Boronic Esters as Chiral Organometallic-Type Nucleophiles for Asymmetric Synthesis
作者:Robin Larouche-Gauthier、Tim G. Elford、Varinder K. Aggarwal
DOI:10.1021/ja2077813
日期:2011.10.26
The addition of an aryllithium reagent to a secondary boronicester leads to an intermediate boron-ate complex that behaves as a chiral nucleophile, reacting with a broad range of electrophiles with inversion of stereochemistry. Depending on the electrophile, the C-B bond can be converted into C-I, C-Br, C-Cl, C-N, C-O, and C-C, all with very high levels of stereocontrol. This discovery now adds a