Regioselective Formation of (
<i>E</i>
)‐β‐Vinylstannanes with a Topologically Controlled Molybdenum‐Based Alkyne Hydrostannation Catalyst
作者:Kyle A. Mandla、Curtis E. Moore、Arnold L. Rheingold、Joshua S. Figueroa
DOI:10.1002/anie.201802397
日期:2018.6.4
long‐standing challenge in transition‐metal‐catalyzed alkynehydrostannation. Herein, we report a well‐defined molybdenum‐based system featuring two encumbering m‐terphenyl isocyanides that reliably and efficiently delivers (E)‐β‐vinylstannanes from a range of terminal and internal alkynes with high regioselectivity. The system is particularly effective for aryl alkynes and can discriminate between alkyl chains
Lewis Acid-Catalyzed Hydrometalation and Carbometalation of Unactivated Alkynes
作者:Naoki Asao、Yoshinori Yamamoto
DOI:10.1246/bcsj.73.1071
日期:2000.5
carbostannation of unactivatedalkynes with organosilanes, or organostannanes proceed effectively in the presence of catalytic amounts of Lewis acids to produce the corresponding vinylsilyl or vinylstannyl compounds in a highly regio- and stereoselective way. Although it is well known that transition metal catalyzed hydrometalations and carbometalations, in general, proceed in a cis-manner, the Lewis acid-catalyzed
A number of alkynes 5, allene 11 and alkene 13 smoothly underwent hydrostannation with tributyltin hydride 1, prepared in situ from tributylchlorostannane 6 and triethylsilane 7 in the presence of catalytic amounts of Lewis acids.
A Lewis acid such as ZrCl4 or HfCl4 catalyses the hydrostannylation of acetylenes 1 to produce the trans-hydrostannylation products 2 regio- and stereo-selectively.
一种路易斯酸,如ZrCl4或HfCl4,催化炔烃1的氢锡化反应,选择性地产生反式氢锡化产物2。
<i>Z</i>-Selective Hydrostannylation of Terminal and Internal C–C Triple Bonds Initiated by the Trityl Cation
作者:Francis Forster、Victoria M. Rendón López、Martin Oestreich
DOI:10.1021/acs.organomet.8b00409
日期:2018.8.27
of n-Bu3SnH across terminal and internal alkynes, including related α,β-unsaturated carboxyl compounds, is reported. The reaction is initiated by the trityl salt [Ph3C]+[B(C6F5)4]− and proceeds through β-tin-stabilized vinyl cations. Their reduction by hydride transfer from n-Bu3SnH explains the high Z-selectivity in the formation of the vinyl stannanes.