Maven property not resolved in parent tag

The following properties are not resolved:

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <java.version>1.8</java.version>
    <spring.boot.version>1.3.3.RELEASE</spring.boot.version>
</properties>

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>${spring.boot.version}</version>
    <relativePath /> <!-- lookup parent from repository -->
</parent>

Non-resolvable parent POM for com.myproject:0.0.1-SNAPSHOT: Failure to find org.springframework.boot:spring-boot-starter-parent:pom:${spring.boot.version}

Does anyone know what do I do wrong?