Boranes organo

Unter Mehrverbrauch von Hydrid wird das Losungsmittel angegriffen. Auch werden Organo-borane gebil-... 

Chlor-bis-[c -hexen-(3)-yl-(3)]-aus 3-Hexin und Chlor-boran 56 Chlor- -Diathylather 7, 54 Dichlor- -THF 7 Dicyclohexyl- 7, 52 Diisopino-campheyl- 7 Herstellung 52 f Disiamyl- 6 -Dimethylamin 9 2,3-Dimethyl-butyl-(2)- 6, 53 Organo- 544 f. 

Marks TJ, Yang S, Stem CL, Chen YXE (1996) Organo-Lewis acids as cocatalysts in cationic metallocene polymerization catalysis. Unusual characteristics of sterically encumbered Tris(perfluorobiphenyl)borane. J Am Chem Soc 118 12451-12452... 

Tetraborane(lO) reacts, as does diborane, readily with unsaturated hydrocarbons. Alkenes give access to B2,B4-alkylene bridged B4H8(RCH-CHR) organo-boranes [37] while alkynes, allenes and l-ene-3-ynes lead to a variety of carba-boranes [38-40]. 

Hydroboration of exo-alkylidene cyclopentane derivatives, for example 70, also proceeds smoothly (BH3.THF, 50 °C, 8h) leading to the migration product in the cydopentane ring only and affording the trans alcohol 73 after oxidation of the organoborane 72 obtained by syn migration of the intermediate tertiary organo-borane 71 (Scheme 14) [7-9]. 

A SIMPLE AND CONVENIENT METHOD FOR THE OXIDATION OF ORGANO-BORANES USING SODIUM PERBORATE (+)-ISOPINOCAMPHEOL... 

Contents Steric and electronic substituent effects on the carbon—carbon bond/Cb. Riichardt, H.-D. Beckhaus — Selective hydroboration and synthetic utility of organo-boranes thus obtained/A. Suzuki, R. S. Dhillon — Synthesis of Y namines/J. Collard-Motte, Z. Janousek — [etc.]... 

Synthesis of secootkiry eokois from l-aOtynes. Dihydroboration at room temperature of a terminal alkyne with either (I) or 9-BBN gives a 1,1-diborylalkane (3) this is treated at 0-5° with I eq. of methyllithium in ether. The product (4) rearranges to (S). An alkyl halide (100 excess) is then added, and the resultant secondary organo-borane (6) is oxidized with alkaline hydrogen peroxide. Secondary alcohols (7) are obtained in 70-85% yield. 

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