Isocyanide diphenylmethyl

Reaction of isoselenocyanates 1579 with a-lithiated a,a-disubstituted isocyanides 1578 such as a,a-methylbenzyl isocyanide and diphenylmethyl isocyanide at —78°C for 1 h affords 2-butylseleno-2-imidazoline-5-selones 1580 after trapping with butyl iodide. The yields for these reactions range from 73% to 97% (Scheme 408) <1997T13667>. 

Shortly after this it was also realized that it is sometimes of interest to convert the U-4CR products into other chemical compounds. In 1983, Isenring and Hofheinz [109] of Hoffmann-La Roche produced a [1-lactam derivative 47 from the diphenylmethyl isocyanide, which could be converted into its derivative 49 [108,109] (Scheme 4.25). 

Diphenylmethyl Isocyanide Diphenylmethyl isocyanide or benzhydryl isocyanide (Ih) is known as the Hofheinz (Isenring) CIC. This odorless crystalline isocyanide can be easily prepared from A-(diphenylmethyl)-formamide (8b) using thionyl chloride and sodium carbonate (Scheme 7.16) [35]. 

In 1981, Isenring and Hofheinz discovered that diphenylmethyl isocyanide can act as a CIC when the Ugi product was treated with N2O4 in CHCI3 at 0°C and warmed to room temperature [36]. The Ugi product a-acylaminoamide 71 forms a nitrosoamide intermediate 72, which converts slowly into the diazo species 73... 

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