Detail of "3319-15-1"

Reference

Ethers - unconventional products of the reduction of aliphatic-aromatic ketones by potassium tetrahydroborate

Ethers - unconventional products of the reduction of aliphatic-aromatic ketones by potassium tetrahydroborate. Potapov, V. M.In this study， 3319-15-1 and 121-89-1 are also used.; Dem'yanovich, V. M.; Khlebnikov, V. A.; Koval'skaya, S. S. (Mosk. Univ., Moscow, USSR). Zh. Org. Khim., 19(12), 2625-6 (Russian) 1983. CODEN: ZORKAE. ISSN: 0514-7492. DOCUMENT TYPE: Journal CA Section: 25 (Benzene, Its Derivatives, and Condensed Benzenoid Compounds) Reducing p-MeOC6H4COMe with KBH4 in aq. ROH (R = Me, Et) contg. NaOH gave 76% p-MeOC6H4CHMeOR (I; same R), along with I (R = H). XC6H4COMe (X = p-Me, p-iodo, p-Br, p-Cl, p-O2N, m-O2N) gave only the coresponding alc. under these conditions. A carbocation intermediate was invoked to explain ether formation. .

Hydroboration

Hydroboration. 66. Addition of lithium triethylborohydride to substituted styrenes. A simple, convenient procedure for the Markovnikov hydroboration of aromatically conjugated olefins and the synthesis of unusual mixed trialkylboranes. Brown, Herbert C.In this study， 3319-15-1 and 122-97-4 are also used.; Kim, Suk Choong (Richard B. Wetherill Lab., Purdue Univ., West Lafayette, IN 47907, USA). J. Org. Chem., 49(6), 1064-71 (English) 1984. CODEN: JOCEAH. ISSN: 0022-3263. DOCUMENT TYPE: Journal CA Section: 29 (Organometallic and Organometalloidal Compounds) Section cross-reference(s): 22 The addn. of Li trialkylborohydride to substituted styrenes and the synthetic applications of the products are described. Styrene, a- and b-methyl-, p-chloro-, and p-methoxystyrene readily undergo the addn. reaction in refluxing THF or in diglyme at 100°. 1,1-Diphenylethylene reacts readily, even at 0°. The double bond in cinnamaldehyde also adds the reagent following initial redn. to the cinnamyl deriv. Substituents that decrease the electron d. at the double bond increase the rate of addn. For the system p-XC6H4CH:CH2, the rate is in the order of X = Cl > H > OMe. trans-b-Methylstyrene and a-methylstyrene react slower than styrene itself. Li tributylborohydride also undergoes these reactions. However, hindered trialkylborohydrides, such as Li triisobutylborohydride and Li tri-sec-butylborohydride, exhibit a slower reaction, which fails to go to completion, even with styrene. The resulting addn. products, Li tetraalkylborates, are transformed into the corresponding arom. hydrocarbons by hydrolysis. More significantly, the protonolysis of these borates with strong acids yields mixed trialkylboranes by selective protonation of the Et group. Oxidn. of these boranes gives only a-ols, indicating that the B atom is attached exclusively to the a-C. The obsd. regiochem. and electronic effects suggest that the reaction involves a nucleophilic attack of R3BH- on the styrene double bond to form the carbanion ArCHMe-, which is trapped by R3B to form the tetraalkylborate product. Consequently, the present method provides a Markovnikov hydroboration of substituted styrenes with exceptional regioselectivity. .