Thought I'd share a few examples of changes when converting to .Net 4.5. The pre-4.5 version is on top and the 4.5 version is on the bottom.

GetRuntimeMethods

typeof(Extensions).GetMethod("methodName")

typeof(Extensions).GetRuntimeMethods().Where(t => t.Name == "methodName").FirstOrDefault()

item.GetType().GetMember("memberName");

item.GetType().GetRuntimeProperties().Where(t => t.Name == "memberName");
and
item.GetType().GetProperties();

item.GetType().GetRuntimeProperties();

GetTypeInfo - Extension

Make sure you add a using for System.Reflection
memberExpression.Member.DeclaringType.IsAssignableFrom(item.GetType())

memberExpression.Member.DeclaringType.GetTypeInfo().IsAssignableFrom(item.GetType().GetTypeInfo())

(CustomCreatedAttribute)Attribute.GetCustomAttribute(item.GetType(), typeof(CustomCreatedAttribute));

item.GetType().GetTypeInfo().GetCustomAttribute<CustomCreatedAttribute>();