172512-89-9

Upstream product

• 695-12-5 vinylcyclohexane 
• 72824-04-5 4,4,5,5-tetramethyl-2-(1-propenyl)-1,3,2-dioxaborolane 
• 1048111-37-0 2-(2-cyclohexylethynyl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane 
• 931-48-6 2-cyclohexylacetylene 
• 25015-63-8 4,4,5,5-tetramethyl-[1,3,2]-dioxaboralane 
• 75927-49-0 pinacol vinylboronate 
• 67404-69-7 (Z)-1-iodo-2-cyclohexyl-1-ethene 
• 185990-03-8 dimethylphenyl(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)silane 
• 73183-34-3 bis(pinacol)diborane 
• 626-62-0 Cyclohexyl iodide 
• 347389-74-6 2-ethynyl-4,4,5,5-tetramethyl-[1,3,2]dioxaborolane 

Downstream Products

• 928648-90-2 (Z)-(5-(2-cyclohexylvinyl)pyridin-2-yl)methanamine 

Relevant academic research and scientific papers

Z-Selective Alkyne Functionalization Catalyzed by a trans-Dihydride N-Heterocyclic Carbene (NHC) Iron Complex

The Z-selective functionalization of terminal alkynes is a useful transformation in organic chemistry and mainly catalyzed by noble metals. Here, we present the Z-selective hydroboration of terminal alkynes catalyzed by a stable trans-dihydride iron compl

Z-Selective Synthesis of Vinyl Boronates through Fe-Catalyzed Alkyl Radical Addition

Z-Selective synthesis of vinyl boronates is challenging. This work describes Fe-catalyzed addition of alkyl radicals, formed by the corresponding alkyl halides, to ethynyl ethynylboronic acid pinacol ester that gives rise to Z-vinyl boronates in high ster

Z-Selective Synthesis of Vinyl Boronates through Fe-Catalyzed Alkyl Radical Addition

Z-Selective synthesis of vinyl boronates is challenging. This work describes Fe-catalyzed addition of alkyl radicals, formed by the corresponding alkyl halides, to ethynyl ethynylboronic acid pinacol ester that gives rise to Z-vinyl boronates in high ster

Direct Synthesis of Alkenylboronates from Alkenes and Pinacol Diboron via Copper Catalysis

We report an efficient approach for the direct synthesis of alkenylboronates using copper catalysis. The Cu/TEMPO catalyst system (where TEMPO = (2,2,6,6-tetramethylpiperidin-1-yl)oxyl) exhibits both excellent reactivity and selectivity for the synthesis of alkenylboronates, starting from inexpensive and abundant alkenes and pinacol diboron. This approach allows for the direct functionalization of both aromatic and aliphatic terminal alkenes. Mechanistic experiments suggest that the alkenylboronates arise from oxyboration intermediates.

Synthesis method of alkenyl boron ester through catalysis of copper

The invention discloses a synthesis method of alkenyl boron ester. The method comprises the following steps: enabling a substrate to carry out olefin dehydroboration esterification reaction with pinacol diborate in a reaction system comprising the substra

Boryl substitution of functionalized aryl-, heteroaryl- and alkenyl halides with silylborane and an alkoxy base: expanded scope and mechanistic studies

A transition-metal-free method has been developed for the boryl substitution of functionalized aryl-, heteroaryl- and alkenyl halides with a silylborane in the presence of an alkali-metal alkoxide. The base-mediated boryl substitution of organohalides with a silylborane was recently reported to provide the corresponding borylated products in good to high yields, and exhibit good functional group compatibility and high tolerance to steric hindrance. In this study, the scope of this transformation has been extended significantly to include a wide variety of functionalized aryl-, heteroaryl- and alkenyl halides. In particular, the boryl substitution of (E)- and (Z)-alkenyl halides proceeded smoothly to afford the corresponding alkenyl boronates in good to high yields with retention of the configuration using modified reaction conditions. The results of the mechanistic studies suggest that this boryl substitution proceeds via a carbanion-mediated mechanism.

Cobalt Catalyzed Z -Selective Hydroboration of Terminal Alkynes and Elucidation of the Origin of Selectivity

A bis(imino)pyridine cobalt-catalyzed hydroboration of terminal alkynes with HBPin (Pin = pinacolate) with high yield and (Z)-selectivity for synthetically valuable vinylboronate esters is described. Deuterium labeling studies, stoichiometric experiments, and isolation of catalytically relevant intermediates support a mechanism involving selective insertion of an alkynylboronate ester into a Co-H bond, a pathway distinct from known precious metal catalysts where metal vinylidene intermediates have been proposed to account for the observed (Z) selectivity. The identity of the imine substituents dictates the relative rates of activation of the cobalt precatalyst with HBPin or the terminal alkyne and, as a consequence, is responsible for the stereochemical outcome of the catalytic reaction.

Synthesis of Z-(pinacolato)allylboron and Z-(pinacolato)alkenylboron compounds through stereoselective catalytic cross-metathesis

The 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 in up to 93% yield and 97% Z selectivity. Z-selective CM with 1,3-dienes and aryl olefins are reported for the first time. The utility of the approach, in combination with catalytic cross coupling, is demonstrated by a concise and stereoselective synthesis of anticancer agent combretastatin A-4.

Straightforward iron-catalyzed synthesis of vinylboronates by the hydroboration of alkynes

An iron-catalyzed hydroboration of alkynes to produce vinylboronates has been examined. With a straightforward system composed of iron carbonyls and pinacolborane, good to excellent yields and chemoselectivities were achieved for a variety of alkynes. Cop

Catalytic non-conventional trans-hydroboration: A theoretical and experimental perspective

We have studied the nonconventional trans-hydroboration reaction of alkynes both experimentally and theoretically. A catalytic system based on the in situ mixture of [{Rh- (cod)Cl}2]/PCy3 (cod=1,5-cyclooctadiene, Cy=cyclohexyl) has been able to activate pinacolborane and catecholborane and transfer boryl and hydride groups onto the same unhindered carbon atom of the terminal alkynes. The presence of a base (Et3N) favored the non-conventional trans-hydroboration over the traditional cis-hydroboration. Varying the substrate had a significant influence on the reaction, with up to 99% conversion and 94% regioselectivity observed for para-methyl- phenylacetylene. Both DFT and quantum mechanical/molecular mechanical ONIOM calculations were carried out on the [RhCl(PR3)2] system. To explain the selectivity towards the (Z)-alkenylboronate we explored several alternative mechanisms to the traditional cishydroboration, using propyne as a model alkyne. The proposed mechanism can be divided into four stages: 1) isomerization of the alkyne into the vinylidene, 2) oxidative addition of the borane reagent, 3) vinylidene insertion into the Rh-H bond, and finally 4) reductive elimination of the C-B bond to yield the 1-alkenylboronate. Calculations indicated that the vinylidene insertion is the selectivity- determining step. This result was consistent with the observed Z selectivity when the sterically demanding phosphine groups, such as PCy3 and PiPr3, were introduced. Finally, we theoretically analyzed the effect of the substrate on the selectivity; we identified several factors that contribute to the preference for aryl alkynes over aliphatic alkynes for the Z isomer. The intrinsic electronic properties of aryl substituents favored the Z-pathway over the E-pathway, and the aryl groups containing electron donating substituents favored the occurrence of the vinylidene reaction channel.