BINAP hydrogen shift

SCHEME 6. Asymmetric 1,3-hydrogen shift catalyzed by BINAP-Rh(I) complexes. 

Scheme 21). Scheme 22 illustrates an example of kinetic resolution of a racemic allylic alcohol with a 1,3-hydrogen shift. When racemic 4-hydroxy-2-cyclopentenone is exposed to a cationic (/ )-BINAP-Rh complex in THF, the S enantiomer is consumed five times faster than the R isomer (32). The slow-reacting stereoisomer purified as the crystalline ferf-butyldimethylsilyl ether is an intermediate in prostaglandin synthesis (33). These isomerizations may occur via initial Rh-olefinic bond interaction (34). 

Benzamido-cinnamic acid, 20, 38, 353 Benzofuran polymerization, 181 Benzoin condensation, 326 Benzomorphans, 37 Benzycinchoninium bromide, 334 Benzycinchoninium chloride, 334, 338 Bifiinctional catalysts, 328 Bifiinctional ketones, enantioselectivity, 66 BINAP allylation, 194 allylic alcohols, 46 axial chirality, 18 complex catalysts, 47 cyclic substrates, 115, 117 double hydrogenation, 72 Heck reaction, 191 hydrogen incorporation, 51 hydrogen shift, 100 hydrogenation, 18, 28, 57, 309 hydrosilylation, 126 inclusion complexes, oxides, 97 ligands, 19, 105 molecular structure, 50, 115 mono- and bis-complexes, 106 NMR spectra, 105 olefin isomerization, 96... 

The cationic BINAP-Rh complexes catalyze asymmetric 1,3-hydrogen shifts of certain alkenes. Diethylgeranylamine can be quantitatively isomerized in THF or acetone to citronellal di-ethylenamine in 96-99% ee (eq 17). This process is the key step in the industrial production of (-)-menthol. In the presence of a cationic (R)-BINAP-Rh complex, (5)-4-hydroxy-2-cyclopentenone is isomerized five times faster than the (R) enantiomer, giving a chiral intermediate of prostaglandin synthesis. ... 

Rose Bengal xanthene dye photosensitizer, 277 Ruthenium, dihydrotetrakis(triphenylphosphine)- double bond shift in alkenes, 270 Ruthenium(2 +), chiral binap complexes asym. hydrogenation with, 102-103, 325-326 Ruthenium(8 +) oxide oxidation with of alcohols to ketones (catalytic), 267 of alkynes to 1,2-diones (catalytic), 117, 132 of ethers to esters, 118, 134-135... 

The BINAP-Rh -catalyzed hydrogenation of enamide 2-acetylamino-3-phenylacrylic acid was studied using the hybrid IMOMM QM/MM method [58]. It was found that the relative energy differences between diastereomers (14-PRO-/ and 14-PRO-5) in both the oxidative addition and migratory insertion steps are consistent with the experimentally observed enantioselectivity. This theoretical evidence shows a shift for this particular ligand-substrate combination as well as the hydrogenation of a-acylaminoacrylates by [Rh((S,S)-dipamp)] to a lock-and-key motif (Scheme 6). 

---