S1 Supporting Information Selective N-Formylation of Amines with H 2 and CO 2 Catalyzed by Cobalt Pincer Complexes Prosenjit Daw, † ‡ Subrata Chakraborty, † ‡ Gregory Leitus, δ Yael Diskin-Posner, δ Yehoshoa Ben-David, † and David Milstein* † Department of † Organic Chemistry and δ Chemical Research Support, Weizmann Institute of Science, Rehovot, 76100, Israel Corresponding Author: *E-mail: david.milstein@weizmann.ac.il. Table of Contents: 1) General procedure………………………………………………. ………...........S2 2) Experimental ………….……………………………………………....................S2 a) Synthesis of complex Co(iPr-PN H P)Cl 2 (1)……………………………………...S2 b) Synthesis of complex [(iPr-PN H P)Co I Cl] (1-Cl)…………………………………S3 c) Reaction of complex 1-Cl with one equiv. NaHBEt 3 and then 1 bar CO 2 ……….S3 d) General procedure for the catalytic reactions ……………………………............S3 e) Procedure for the catalytic reaction using 1-Cl…………………………………..S4 f) Procedure for the catalytic reaction using 1-Cl and NaHBEt 3 …………………...S5 g) Reaction of complex 1-Cl with HCOONa to form a formate complex………… S5 h) Catalytic reaction using complex 1 in presence of KOH and absence of amine….S6 i) Formylation of dimethylamine catalyzed by 1 using low catalyst loading…….………S6 3) X-ray structure determination data…………………………………….……………...S7 4) GC-MS data of various substrate and formamides…………………...……………..S10 5) 1 H and 13 C NMR data and NMR spectra of formamides……………...…………….S12 6) References………………………………………………………...………………....S29