Big corporations mostly have corporate giving programs, but they are designed for the "greater good" and not for individual's enrichment purposes such as starting businesses. Like the federal government, private foundations including corporations hardly give grant to those who wish to start a business.

Here are some of the big companies' corporate giving programs and their objectives:

Dell Foundation http://www.dell.com/content/topics/global.aspx/cor p/foundation/en/index?c=us&l=en&s=corp
Recipients are 501(c)(3) non-profit organization and objective is to address the health and human services, the education, and the technology access for youth. Specifically says that they do NOT provide grants for individuals

Microsoft http://www.microsoft.com/citizenship/giving/
Provides support to Community-Based Technology and Learning Center (CTLC) organizations including Nonprofit—in the United States, 501(c)(3) designation—or a nongovernmental organization; Government funded and operated—a nonprofit organization that receives government funding or is a partner with a governmental; and schools. Specifically says that they do NOT give to individuals

Philip Morris http://www.philipmorrisusa.com/en/our_initiatives/ community_involvement.asp
Provides financial and in-kind contributions to local organizations, and through sponsorship of community events. Again, applicants must be non-profit, charitable organizations tax-exempt under section 501(c)(3) of the Internal Revenue Code. Individuals are again NOT eligible.