Boranes ethylene derivatives

Reaction of boranes with diazo compounds Synthesis of ketones from ethylene derivatives... 

Borane-hydrogen peroxide sodium hydroxide Alcohols from ethylene derivs. 

Borane hydro gen chloride Ethylene derivs. from enoxysilanes... 

Borane-tetrahydrofuranitrimethylsilyl azide Prim, amines from ethylene derivs. under neutral conditions... 

Hydroboration (s. a. Boranes from ethylene derivatives, Brown hydration)... 

Di(isopinocampheyl)borane Resolution of racemic ethylene derivatives with optically active boranes s. 19, 720 Lithium tetrahydridoborate s. under (C2H )gN,HCl Sodium tetrahydridoborate/boron fluoride Boranes from ethylene derivatives s. 16, 753... 

Cyanogen bromide borane Synthesis of tran -ethylene derivs. from acetylene derivs. 

Tri(cyclopentyl)borane in diglyme added at 0° to Li-n-hexylacetylide under hexane, the volatile solvent removed, methyl tosylate added at -78°, the cooling bath removed, warmed 2 hrs. at 40°, then oxidized with alkaline H2O2 -> product. Y 88%. F. e., also with other alkylating agents such as bromides, sulfates, or oxonium salts, protonation with methanesulfonic acid, and synthesis of mixtures of cis- and trans-ethylene derivs., s. A. Pelter, C. R. Harrison, and D. Kirkpatrick, Chem. Commun. 1973, 544. 

The development 0/ the chemistry of boranes continues with outstanding results It has produced a convenient route to the less stable, terminally unsaturated compounds from the more stable, highly substituted ethylene derivatives , a facile procedure for the asymmetric synthesis of alcohols of high optical purity , and a... 

Sodium boron hydride/boron fluoride Boranes from ethylene derivatives s. 15, 69... 

Amines can be obtained under mild conditions from amides by reduction with borane and also from ethylene derivatives with borane and hydroxylamine-O-sulfonic acid or chloramine A modified Schmidt reaction gives good yields of N-subst. trifluoro-acetamides... 

Di(isopinocampheyl)borane Resolution of racemic ethylene derivatives with optically active horanes... 

Aldehydes of different types can be conveniently prepared from the next lower halides through carbinols which are split by dia-zotized sulfanilic acid Aliphatic aldehydes in particular can be easily obtained from carboxylic acids through N-acylethylenimi-es Aldehydes, in turn, can be converted directly into nitriles with hydroxylamine hydrochloride Ketones can be efficiently prepared from ethylene derivatives via boranes and, in high purity, from labile alcohols by oxidation in an aq.-ethereal two-phase medium Heating aliphatic acids with reduced iron powder proved to be an excellent method for the prepn. of sym. straight-chain ketones /5-Aminoketones unobtainable by Mannich reaction may be prepared via halogenomagnesium enolates... 

Via intermediates Synthesis of hydrocarbons from ethylene derivatives via boranes A new general coupling reaction... 

Coupling of ethylene derivatives via boranes Synthesis of 0x0 compounds from ot,/ -ethylenoxo compounds... 

Support-bound 1,2-diamines can be readily converted into imidazolidinones by treatment with carbonyl diimidazole [128,129]. The required diamines have been prepared on cross-linked polystyrene by reduction of peptides bound to MBHA resin with borane. Similarly, bicyclic imidazolines have been prepared from triamines and thiocarbonyl diimidazole (Entry 10, Table 14.3). Dehydration of polystyrene-bound monoacyl ethylene-1,2-diamines yields 4,5-dihydroimidazoles (cyclic amidines, Entry 5, Table 13.18). Several groups have reported the synthesis of 2-aminoimidazol-4-ones from resin-bound amino acid derivatives (e.g., Entry 6, Table 15.11). Most of these compounds are, however, unstable, and slowly decompose if dissolved in DMSO (Jesper Lau, private communication). 

Monaharan has developed a versatile synthetic route for the synthesis of 2 -0-[(N, iV-dimethylamino)-oxyethyl] modified purine and pyrimidine nucleoside phosphoramidites (63a-d) to be used as antisense oligonucleotide building blocks. In the syntheses of the purine-based analogues, the (iV, N-dimethylamino)-oxyethyl group was introduced via a 2 -allyloxy nucleoside intermediate, while the pyrimidine-based nucleosides were obtained from the TBDMS-protected 2,2 -anhydro-5-methyluridine via ring opening reaction in the presence of borane and ethylene glycol. The aminoxy derivatives were... 

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