Ethynyl derivatives of formula I wherein U is =N- or =C(R 5)-; V is -CH= or N=; W is =CH- or =N-; with the proviso that only one of U, V or W can be nitrogen. R 5 is hydrogen, methyl or halogen; Y is -N(R 6 -O-, -C(R 7')(R 7)-, -CH 2 O- or -CH 2 S 2 -; wherein R 6 is hydrogen or C 1-4 -alkyl and R 7 /R 7' are independently from each other hydrogen, hydroxy, C 1-4 -alkyl or C 1-4 -alkoxy; R 1 is phenyl or heteroaryl, which are optionally substituted by one or two substituents, selected from halogen, C 1-4 -alkyl or C 1-4 -alkoxy; R 2 /R 2' are independently from each other hydrogen, C 1-4 -alkyl, hydroxy, C 1-4 -alkoxy, C 3 -C 6 -cycloalkyl, CH 2 - C 1-4 -alkoxy, or may form together with the carbon atom to which they are attached a C 3 -C 6 -cycloalkyl or a ring containing -CH 2 OCH 2 -; m is 0, 1 or 2; in case m is 1, R 3 /R 3' are independently from each other hydrogen, C 1-4 -alkyl, CH 2 - C 1-4 -alkoxy or may form together with the carbon atom to which they are attached a C 3 -C 6 -cycloalkyl; or R 3 and R 2 may form together with the carbon atom to which they are attached a C 3-6 -cycloalkyl or a ring containing -(CH 2) 2 OCH 2 -; n is 0 or 1; in case n is 1, R 4 /R 4' are independently from each other hydrogen, C 1-4 -alkyl, CH 2 -C 1-4 -alkoxy or may form together with the carbon atom to which they are attached a C 3 -C 6 -cycloalkyl; R 4 and R 2 may form together with the carbon atom to which they are attached a C 3-6 -cycloalkyl; or if n is 0 and Y is -N(R 6)-, then R 6 and R 2 may form together with the carbon atom and the nitrogen atom to which they are attached a C 3-6 -cycloalkyl; or if n and m are 0, then R 2 and R 7 may form together with the carbon atoms to which they are attached a C 3-6 -cycloalkyl; or a pharmaceutically acceptable acid addition salt, a racemic mixture, or its corresponding enantiomer and/or optical isomer and/or stereoisomer thereof. U is =N- or =C(R 5)-; V is -CH= or N=; W is =CH- or =N-; with the proviso that only one of U, V or W can be nitrogen. R 5 is hydrogen, methyl or halogen; Y is -N(R 6 -O-, -C(R 7')(R 7)-, -CH 2 O- or -CH 2 S 2 -; wherein R 6 is hydrogen or C 1-4 -alkyl and R 7 /R 7' are independently from each other hydrogen, hydroxy, C 1-4 -alkyl or C 1-4 -alkoxy; R 1 is phenyl or heteroaryl, which are optionally substituted by one or two substituents, selected from halogen, C 1-4 -alkyl or C 1-4 -alkoxy; R 2 /R 2' are independently from each other hydrogen, C 1-4 -alkyl, hydroxy, C 1-4 -alkoxy, C 3 -C 6 -cycloalkyl, CH 2 - C 1-4 -alkoxy, or may form together with the carbon atom to which they are attached a C 3 -C 6 -cycloalkyl or a ring containing -CH 2 OCH 2 -; m is 0, 1 or 2; in case m is 1, R 3 /R 3' are independently from each other hydrogen, C 1-4 -alkyl, CH 2 - C 1-4 -alkoxy or may form together with the carbon atom to which they are attached a C 3 -C 6 -cycloalkyl; or R 3 and R 2 may form together with the carbon atom to which they are attached a C 3-6 -cycloalkyl or a ring containing -(CH 2) 2 OCH 2 -; n is 0 or 1; in case n is 1, R 4 /R 4' are independently from each other hydrogen, C 1-4 -alkyl, CH 2 -C 1-4 -alkoxy or may form together with the carbon atom to which they are attached a C 3 -C 6 -cycloalkyl; R 4 and R 2 may form together with the carbon atom to which they are attached a C 3-6 -cycloalkyl; or if n is 0 and Y is -N(R 6)-, then R 6 and R 2 may form together with the carbon atom and the nitrogen atom to which they are attached a C 3-6 -cycloalkyl; or if n and m are 0, then R 2 and R 7 may form together with the carbon atoms to which they are attached a C 3-6 -cycloalkyl;