The regioselective synthesis of 2,3-di- and 1,2,3-trisubstituted naphthalenes via Directed ortho Metalation (DoM) strategies of N,N-diethyl-O-naphthyl-2-carbamate (1) is presented. Sequential LiTMP metalation-electrophile quench and s-BuLi/TMEDA (or t-BuLi)-electrophile quench of naphthyl-2-carbamate 1 provides a general route to contiguously substituted naphthalenes (6) with full regioselectivity. Further derivatization via ipso-halodesilylation and Suzuki-Miyaura cross-coupling leads ultimately to substituted halonaphthalenes and benzonaphthopyranones (9).

A general, mild, and efficient method for the reductive cleavage of aryl O-carbamates to phenols, 1 → 2 using the Schwartz reagent is reported. The method is selective, tolerating a large number of functional groups; may be carried out by direct or by an economical in situ procedure; and, notably, establishes a synthetic connection to the directed ortho metalation strategy (Figure 1 ) allowing new entries into difficult to prepare contiguously substituted aromatics and heteroaromatics.

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Directed ortho Metalation Strategies. Effective Regioselective Routes to 1,2-, 2,3-, and 1,2,3-Substituted Naphthalenes. -Directed ortho-metalation of naphthyl--2-carbamate followed by reaction with various electrophiles affords di-and trisubstituted naphthalenes with high regioselectivity. Further derivatization of product (XIV) via ipso-halodesilylation provides dihalonaphthalene (XV). A three step sequence involving Suzuki-Miyaura coupling, Fries rearrangement, and cyclization allows the conversion of product (XIV) into benzonaphthopyranones (XIX). -(GROOM, K.; HUSSAIN, S. M. S.; MORIN, J.; NILEWSKI, C.; RANTANEN, T.; SNIECKUS*, V.; Org. Lett. 16 (2014) 9, 2378-2381, http://dx.doi.org/10.1021/ol500707w ; Dep. Chem., Queen's Univ., Kingston, Ont. K7L 3N6, Can.; Eng.) -Mais 46-051

Reductive Cleavage of Aryl O-Carbamates to Phenols by the Schwartz Reagent. Expedient Link to the Directed ortho Metalation Strategy. -The efficient new method is selective and tolerates a large number of functional groups. The reaction can be carried out by direct or by an economical in situ procedure. In synthetic connection to the directed ortho metalation strategy, the procedure allows access to substituted aromatics and heteroaromatics which are difficult to prepare otherwise. -(MORIN, J.; ZHAO, Y.; SNIECKUS*, V.; Org. Lett. 15 (2013) 16, 4102-4105, http://dx.doi.org/10.1021/ol401547d ; Dep. Chem., Queen's Univ., Kingston, Ont. K7L 3N6, Can.; Eng.) -S. Adam 01-072