A traditional 'brochure style' website won't work. Senior Executives in huge corporations mostly already have relationships with the traditional big name consultancies. You will reach them by making their gatekeepers look great. To do that you need to solve their gatekeepers' problems. Your website needs to provide huge amounts of help to them. Over months as you develop trust and understand their situation more then you will start to make progress. It is crucial to differentiate from the big name consultancies.