SEARCH Articles Figures Tables 3-formyl-pyrrole Formylations, Vilsmeier-Haack Haack Haack Formylation Pyrroles, formylation Vilsmeier Vilsmeier formylation Vilsmeier-Haack Vilsmeier-Haack formylation Vilsmeier-Haack formylation/acylation pyrroles