Metal-free disproportionation of formic acid mediated by organoboranes
作者:Clément Chauvier、Pierre Thuéry、Thibault Cantat
DOI:10.1039/c6sc01410k
日期:——
In the presence of dialkylboranes, formic acid can be converted to formaldehyde and methanol derivatives without the need for an external reductant. This reactivity, in which formates serve as the sole carbon and hydride sources, represents the first example of the disproportionation of formate anions under metal-free conditions. Capitalizing on both experimental and computational (DFT) mechanistic
synthesis of boron heterocycles from borinic and boronic esters with α-aminoacids was explored as a means of upgrading the optical purities of intermediates from asymmetric hydroboration. B-Methoxy-9-borabicyclo[3.3.1]nonane, methyl dicyclohexylborinate and (+)- and (-)-methyl diisopinocampheylborinate react with various α-aminoacids to form the corresponding crystalline chelates. Recrystallization
The reaction of organolithium reagents with methyl-dialkylborinates in hydrocarbon solvents proceeds readily with precipitation of lithium methoxide and the formation of the corresponding mixed organoborane: Consequently, simple filtration of the reaction mixture gives the mixed organoborane in high yield and purity. Other dialkylborane derivatives, such as the chloride and the hydride, are less desirable
Method for Preparing Methoxyboranes and for Producing Methanol
申请人:Commissariat a l'Energie Atomique et aux Erergies Alternatives
公开号:US20180327430A1
公开(公告)日:2018-11-15
The present disclosure relates to a method for preparing methoxyboranes by dismutation of formic acid or at least one of the derivatives thereof or a mixture of formic acid and at least one of the derivatives thereof, in the presence of an organoborane, and optionally an organic or inorganic base.
Generation of o-quinodimethanes via the electrocyclic reaction of (4Z)-1,2,4,6,7-octapentaenes derived from the organoborate complexes and their subsequent reactions
作者:Quan Zhang、Kung K Wang
DOI:10.1016/s0022-328x(99)00056-x
日期:1999.6
reaction then generated the o-quinodimethane 24, which underwent a [1,5]-sigmatropic hydrogen shift to afford 25. Oxidative work-up followed by protonation gave the phenol 26. The presence of a boron group and a tin group in 25 also provides handles to allow their transformations to an allyl substituent and an iodo substituent in 27. Attempts to capture the o-quinodimethane in 32 with the carbon–carbon