96493-72-0

Upstream product

• 56881-81-3 4-tert-butyl-1-dibromomethylenecyclohexane 
• 1034-49-7 (bromomethyl)triphenyl phosphonium bromide 
• 98-53-3 4-tercbutyl-cyclohexanone 
• 96493-77-5 1-((R)-4-tert-Butyl-cyclohexylmethanesulfinyl)-4-methyl-benzene 
• 96493-69-5 1-[(R)-(R)-Bromo-(4-tert-butyl-cyclohexyl)-methanesulfinyl]-4-methyl-benzene 
• 97634-88-3 cis-4-(t-butyl)-1-(phenylsulfonyl)cyclohexane 
• 74-95-3 1,1-dibromomethane 

Downstream Products

• 140402-02-4 4-tert-butyl-1-(2-trimethylsilylvinyl)cyclohexane 

Relevant academic research and scientific papers

Lithium carbenoids-ultra-reactive yet selective reagents for methylenation and halomethylenation of sulfones

The first efficient, one-pot method for methylenation of p-toluyl sulfones (i.e., the transformation of p-MePhSO2CHR2 into R 2CCH2) is described. Methods for effecting that transformation involving alkylation of sulfones with reagents of the general formula MCH2X, where M = SiMe3, SnR3, and MgCl (the Julia method) have been previously described. However, the silicon reagent is completely unreactive toward many sulfones, the tin reagent typically affords only moderate yields, and the magnesium reagent typically gives incomplete reaction (9-40% starting material). This article reports that excellent yields are obtained by alkylating the sulfone with the more ionic lithium methylene carbenoids (LiCH2X, where X = Cl, Br, and I). For example, treatment of sulfone 1 with 3 equiv of n-BuLi (THF, -100 °C) followed by 2 equiv of CH2Br2 affords olefin 2 in 96% yield. Although the carbenoid is generated in the presence of a 1:2 mixture of α-lithio- sulfone and n-BuLi, it reacts selectively with the α-lithio-sulfone (Krel = 9.6 ± 0.8 with LiCH2Br). The chlorocarbenoid LiCH2Cl reacts somewhat less selectively (K rel = 3.5). The alkylsubstituted carbenoid n-BuCHBrLi reacts ≥ 40 times more slowly than LiCH2Br, suggesting that olefination occurs by the SN2 mechanism rather than by metal-assisted ionization (MAI), the mechanism by which cyclopropyl and vinylidene carbenoids react with nucleophiles. Finally, sulfones can be transformed into vinyl halides by treatment with 3 equiv of n-BuLi (THF, -78 °C), followed by >2 equiv of diisopropylamine, followed by 3 equiv of dihalomethane (CH2X 2, where X2 = Cl2, BrCl, Br2, or I2). All products are formed in high yield and purity.

A facile route to vinyl- and arylphosphonates by vinyl and aryl radical trapping with (MeO)3P

The generation of vinyl or aryl radicals under classical, thermal AIBN/n-Bu3SnH conditions at 80 °C in the presence of an excess of (MeO)3P gives rise to the corresponding vinyl- or arylphosphonates in good yields. This approach comp

Reactions of 1,1-Dihaloalkenes with Triorganozincates: A Novel Method for the Preparation of Alkenylzinc Species Associated with Carbon-Carbon Bond Formation

Lithium trialkylzincates react with 1,1-dibromoalkenes 1 and 1-bromo-1-chloroalkenes 2 at -85 deg C in THF to give 1-bromoalkenes 5 and 1-chloroalkenes 7, respectively, upon hydrolysis.The intermediate (1-haloalkenyl)zincates 4 and 6 are stable at low temperature but, when allowed to warm to 0 deg C, they undergo a 1,2-alkyl migration reaction to afford alkenylzinc species 10.A variety of alkylation products 11 are obtained by the hydrolysis of 10.In the presence of (Ph3P)2Pd (5 molpercent), alkenylzinc species 10 react smoothly with organic halides (AcCl, EtOCOCl, CH2=CH(Me)Br, PhBr) to yield the corresponding coupling products 13-16.

GENERATION AND ALKYLATION REACTION OF 1-BROMOALKENYLZINCATE

1-Bromoalkenylzincates (R1R2C=CBrZnR32Li) which are generated by the reaction of 1,1-dibromoalkenes with a lithium triorganozincate (R33ZnLi) at -85 deg C undergo alkylation reaction at temperatures from -85 deg C to 0 deg C to give alkenes R1R2C=CHR3.

ENANTIOSPECIFIC SYNTHESIS OF OPTICALLY ACTIVE CYCLOHEXYLIDENE BROMOMETHANES

Optically pure cyclohexylidene bromomethanes were prepared by stereospecific bromination alpha to a chiral sulfoxide, followed by the stereospecific pyrolytic elimination of the sulfoxide moiety.