comparable reactivity to transition-metal-catalysed hydroboration protocols. Simple, commercially available borane adducts, H3B·THF and H3B·SMe2, have been used to catalyse the hydroboration of alkynes and alkenes with pinacolborane to give the alkenyl and alkyl boronic esters, respectively. Alkynes and terminal alkenes underwent highly regioselective hydroboration to give the linear boronic ester products.
Stable, Yet Highly Reactive Nonclassical Iron(II) Polyhydride Pincer Complexes: <i>Z</i>-Selective Dimerization and Hydroboration of Terminal Alkynes
作者:Nikolaus Gorgas、Luis G. Alves、Berthold Stöger、Ana M. Martins、Luis F. Veiros、Karl Kirchner
DOI:10.1021/jacs.7b05051
日期:2017.6.21
polyhydride complexes containing tridentate PNP pincer-type ligands is described. These compounds of the general formula [Fe(PNP)(H)2(η2-H2)] exhibit remarkable reactivity toward terminalalkynes. They efficiently promote the catalytic dimerization of aryl acetylenes giving the corresponding conjugated 1,3-enynes in excellent yields with low catalyst loadings. When the reaction is carried out in the presence
描述了含有三齿 PNP 钳型配体的非经典铁 (II) 氢化物配合物的合成、表征和催化活性。这些通式[Fe(PNP)(H)2(η2-H2)]的化合物对末端炔表现出显着的反应性。它们有效地促进芳基乙炔的催化二聚化,以极低的催化剂负载量以优异的产率得到相应的共轭 1,3-烯炔。当反应在频哪醇硼烷存在下进行时,得到乙烯基硼酸酯。这两个反应都在温和的条件下进行,并且具有高度的化学选择性、区域选择性和立体选择性,Z 选择性高达 99%。
Synthesis of <i>Z</i>-(Pinacolato)allylboron and <i>Z</i>-(Pinacolato)alkenylboron Compounds through Stereoselective Catalytic Cross-Metathesis
作者:Elizabeth T. Kiesewetter、Robert V. O’Brien、Elsie C. Yu、Simon J. Meek、Richard R. Schrock、Amir H. Hoveyda
DOI:10.1021/ja403188t
日期:2013.4.24
first examples of catalytic cross-metathesis (CM) reactions that furnish Z-(pinacolato)allylboron and Z-(pinacolato)alkenylboron compounds are disclosed. Products are generated with high Z selectivity by the use of a W-based monoaryloxide pyrrolide (MAP) complex (up to 91% yield and >98:2 Z:E). The more sterically demanding Z-alkenylboron species are obtained in the presence of Mo-based MAP complexes
公开了提供Z-(频哪醇)烯基硼和Z-(频哪醇)烯基硼化合物的催化交叉复分解(CM)反应的第一实例。通过使用 W 基单芳氧基吡咯 (MAP) 络合物,生成具有高 Z 选择性的产品(产率高达 91%,Z:E >98:2)。在 Mo 基 MAP 配合物存在下,可以获得空间要求更高的 Z-烯基硼物质,产率高达 93%,Z 选择性高达 97%。首次报道了 1,3-二烯和芳基烯烃的 Z 选择性 CM。该方法与催化交叉偶联相结合的实用性通过抗癌剂考布他汀 A-4 的简洁和立体选择性合成得到了证明。
(<i>Z</i>)-Selective Hydroboration of Terminal Alkynes Catalyzed by a PSP–Pincer Rhodium Complex
作者:Yanzong Lyu、Naoyuki Toriumi、Nobuharu Iwasawa
DOI:10.1021/acs.orglett.1c03606
日期:2021.12.3
A highly (Z)-selective hydroboration of terminal alkynes was achieved using a thioxanthene-based PSP–pincer rhodium catalyst. This hydroboration exhibited good chemoselectivity toward alkynes over carbonyl compounds such as ketones and aldehydes. The mechanistic studies indicated the involvement of rhodium–vinylidene intermediates, and the high (Z)-selectivity could be attributed to the rigid and electron-rich
使用基于噻吨的 PSP-钳形铑催化剂实现了末端炔烃的高 ( Z ) 选择性硼氢化反应。与羰基化合物(如酮和醛)相比,这种硼氢化反应对炔烃表现出良好的化学选择性。机理研究表明铑-亚乙烯基中间体的参与,高(Z)选择性可归因于 PSP-铑催化剂的刚性和富电子性质。
Synthesis of 1,1-Organodiboronates
via Rh(I)Cl-Catalyzed Sequential Regioselective Hydroboration
of 1-Alkynes
作者:Kohei Endo、Takanori Shibata、Munenao Hirokami
DOI:10.1055/s-0028-1088131
日期:——
A Rh(I)Cl-DPPB-complex-catalyzed sequential hydroboration of aryl alkynes and aliphatic alkynes was achieved. The reaction proceeded with almost perfect regioselectivity to afford 1,1-organodiboronate compounds in moderate to good yield.