182211-19-4

Upstream product

• 14371-10-9 (E)-3-phenylpropenal 
• 693-04-9 butyl magnesium bromide 
• 154081-22-8 (E)-styrylboronic acid 1,3-propandiol ester 
• 110-62-3 pentanal 
• 78350-68-2 chlorotitanium triisopropoxide 
• 109-72-8 n-butyllithium 
• 1119-90-0 di-n-butylzinc 

Relevant academic research and scientific papers

Accessing Both Retention and Inversion Pathways in Stereospecific, Nickel-Catalyzed Miyaura Borylations of Allylic Pivalates

We have developed a stereospecific, nickel-catalyzed Miyaura borylation of allylic pivalates, which delivers highly enantioenriched α-stereogenic γ-aryl allylboronates with good yields and regioselectivities. Our complementary sets of conditions enable access to either enantiomer of allylboronate product from a single enantiomer of readily prepared allylic pivalate substrate. Excellent functional group tolerance, yields, regioselectivities, and stereochemical fidelities are observed. The stereochemical switch from stereoretention to stereoinversion largely depends upon solvent and can be explained by competitive pathways for the oxidative addition step. Our mechanistic investigations support a stereoretentive pathway stemming from a directed oxidative addition and a stereoinvertive pathway that is dominant when MeCN blocks coordination of the directing group by binding the nickel catalyst.

Catalytic asymmetric addition of aldehydes using organolithium reagents in the presence of commercial available chiral diol ligands

An efficient method for the catalytic asymmetric additions to aldehydes using organolithium reagents and titanium(IV) isopropoxide in the presence of commercially available and relatively inexpensive diol ligands, such as (S)-BINOL or D-TADDOL has been developed. Good to excellent yields (up to 92%) and enantioselectivities (up to 94%) of the corresponding secondary alcohol products can be obtained following a simple procedure at relatively mild reaction temperatures.

Room temperature and highly enantioselective additions of alkyltitanium reagents to aldehydes catalyzed by a titanium catalyst of (R)-h 8-binol

Three alkyltitanium reagents of RTi(O-i-Pr)3 (R = Cy (1a), i-Bu (1b), and n-Bu (1c)) were prepared in good yields. The high-resolution mass spectroscopy showed that 1b and 1c in the gas phase are monomeric species. However, the solid state of 1a revealed a dimeric structure. Asymmetric additions of 1a-1c to aldehydes catalyzed by a titanium catalyst of (R)-H 8-BINOL were studied at room temperature. The reactions produced desired secondary alcohols in good yields with good to excellent enantioselectivities of up to 94% ee. Reactivity and enantioselectivity differences, in terms of steric bulkiness of the R nucleophiles, are herein described. The addition reactions of secondary c-hexyl to aldehydes were slower than the reactions of primary i-butyl or n-butyl nucleophiles. For the primary alkyls, lower enantioselectivities were obtained for products from addition reactions of the linear n-butyl as compared with the enantioselectivities of products from the addition reactions of the branched i-butyl group. The same stereochemistry of RTi(O-i-Pr)3 addition reactions as the addition reactions of organozinc, organoaluminum, Grignard, or organolithium reagents directly supports the argument of that titanium-catalyzed addition reactions of aldehydes involve an addition of an organotitanium nucleophile.

Enantioselective addition of alkenylzinc reagents to aldehydes with organoboronates as the alkenyl source

Alkenylboronates were used as a vinyl source in the asymmetric addition of an alkenylzinc reagent to aldehydes catalyzed by a dendritic ligand. The resulting allylic alcohol products were obtained in 66-96% ee and 35-64% yields.

Enantioselective addition of tris(TADDOL) organocerium reagents to aldehydes

A significant improvement in enantioselectivity (up to 92% ee) was achieved in butyl additions to a range of aldehydes with a novel tris(TADDOL) organocerium reagent.

Preparation of polyfunctional diorganomercurials and their transmetallation to diorganozincs. Applications to the preparation of optically active secondary alcohols

Two new methods of preparation of functionalized diorganomercurials have been developed.The first method involves a substitution reaction of (ICH2)2Hg with zinc-copper reagents FG-RCu(CN)ZnI in THF/DMF at -60 deg C.Functional groups such as an ester, nitrile, ketone, phosphonate, halide, and boronic ester are tolerated in this reaction.The second method involves a reductive transmetallation between polyfunctional organozinc halides and mercurous chloride (Hg2Cl2).This very convenient procedure provides a rapid route to various functionalized diorganomercurials in good yields (61-89percent yield).The synthetic utility of these mercury organometallics is demonstrated.Their transmetallation with zinc dust (toluene, 80 deg C, 3-5 h) affords dialkylzincs which add enantioselectively to aldehydes in the presence of a catalytic amount (20 molpercent) of the norephedrine derivative 13.This transmetallation can also be used to prepare stereoselectively (E)-alkenylzinc halides (> 98percent E).Addition of Cl(H)ZrCp2 to (E)-5-chloropentenylzinc bromide in CH2Cl2 (25 deg C, 1 min) affords a 1,1-bimetallic of zinc and zirconium Cl(CH2)4CH(ZnBr)ZrCp2(Cl) which reacts stereoselectively with an aldehyde providing the (E)-disubstituted olefin (49percent yield; 100percent E).