Cyclopentyl methyl ether CPME

Ar= Ph, 4-MeOCeH4 4-FC6H4,4-f-BuC6H4.4-N(Me)2C6H4,4-CIC6H4.2-MeC6H4,1-naphthyl, 5-benzofuryl, 5-W-Methylindolyl-CPME= cyclopentyl methyl ether... 

A BINOL-dimethylaminopyridine hybrid was seen to be efficient in mediating the MBH reaction (Table 5.14) [96], with optimal reaction conditions being found as —15 °C with a mixed solvent system consisting of toluene and cyclopentyl methyl ether (CPME) in a 1 9 ratio. The reaction was sensitive to the structure of the catalyst 112, the position of the Lewis base attached to BINOL, the substitution pattern of the amino group, and the length of the spacer. It should be noted that the bulky i-Pr substituent on the amino group showed the best selectivity and kinetic profile (Table 5.14, entry 5) [98]. (For experimental details see Chapter 14.10.4). 

Cyclopentyl methyl ether (CPME) is another alternative to typical ethereal solvents such as diethyl ether, THF, DME and dioxane. At present it is not bio-sourced but it is mentioned here as it has many advantageous properties as a direct replacement for ethers. Most importantly, the rate of peroxide formation is very slow and therefore, CPME is green in terms of risk avoidance and other criteria. Its use in a range of classical and modern synthetic procedures has been reported. ... 

CPME spinning cyclopentyl methyl ether DDQ dehydroabietylisothiocyanate 2,3-dichloro-5,6-dicyano-1,4-... 

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