Facile Conversion of Aldehydes and Ketones to gem-Dichlorides Using Chlorodiphenylphosphine/N-Chlorosuccinimide as a New and Neutral System

Abstract

Aldehydes and ketones are easily converted to their corresponding gem-dichlorides using a mixture of chlorodiphenylphosphine and N-chlorosuccinimide (ClPPh₂/NCS) in dichloromethane under neutral conditions and at room temperature.

Keywords:

• Aldehyde
• chlorodiphenylphosphine
• gem-dichloride
• ketone
• N-chlorosuccinimide

ACKNOWLEDGMENT

We gratefully acknowledge the support of this work by Damghan University of the Basic Sciences Research Council.

Notes

^a Molar ratio is related to aldehyde/tertiary phosphine/NCS.

^b This reaction was carried out in acetonitrile as solvent.

^a Molar ratio is related to aldehyde or ketone/ClPPh₂/NCS.

^b Isolated yields.

^c In this case, equimolar amounts of the related gem-dichloride 10 and 1-(1-chloroethenyl)-4-nitrobenzene 13 were obtained on the basis of NMR analysis.

^d Bp 71–72°C (4 mm) (lit.^[15] 71°C, 4 mm).

^e NBS was used instead of NCS in this case.

^f A mixture of dibromomethylbenzene 12 and bromochloromethylbenzene 14 was produced in a 4:1 ratio together with a trace amount of dichloromethylbenzene 7 in this case.