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1. Regioselective Formation of Substituted Indoles: Formal Synthesis of Lysergic Acid

   https://doi.org/10.1002/chem.202004107  

   Points, III, Gary_L; Stout, Kenneth_T; Beaudry, Christopher_M (November 2020, Chemistry – A European Journal)

   Abstract A Diels–Alder reaction‐based strategy for the synthesis of indoles and related heterocycles is reported. An intramolecular cycloaddition of alkyne‐tethered 3‐aminopyrones gives 4‐substituted indolines in good yield and with complete regioselectivity. Additional substitution is readily tolerated in the transformation, allowing synthesis of complex and non‐canonical substitution patterns. Oxidative conditions give the corresponding indoles. The strategy also allows the synthesis of carbazoles. The method was showcased in a formal synthesis of lysergic acid. 

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2. Rhodium( i )-catalyzed directed trideuteromethylation of (hetero)arene C–H bonds with CD ₃ CO ₂ D

   https://doi.org/10.1039/D2OB01581A  

   Zhao, Haoqiang; Zeng, Qi; Yang, Ji; Xu, Bing; Lei, Haimin; Xu, Lijin; Walsh, Patrick J. (October 2022, Organic & Biomolecular Chemistry)

   A Rh( i )-catalyzed trideuteromethylation of heteroarenes with inexpensive and readily available deuterated acetic acid (CD 3 CO 2 D) with the aid of a N -containing directing groups is developed. The oxidant-free reaction is applicable to a wide range of heteroarene substrates, including 2-pyridones, indoles, aryl rings, pyrroles and carbazoles. It allows installation of CD 3 groups under straightforward reaction conditions. It is expected that the salient and practical features of this trideuteromethylation protocol will be of use to academic and industrial researchers. 

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3. A Unified Approach to Mono- and 2,3-Disubstituted N–H Indoles

   https://doi.org/10.1055/s-0042-1752656  

   Kim, Ju Hee; Lee, Sun A; Jeon, Tae Sik; Cha, Jin Kun; Kim, Young Gyu (August 2023, Synlett)

   Abstract A unified approach to mono- and disubstituted N–H indoles is described by means of oxidative cyclization of 2-alkenyl anilines, which are prepared by cross-coupling of the corresponding o-bromoanilines. This procedure is operationally expedient and tolerant of common functional groups to allow regiospecific installation of the alkyl and aryl substituents. 

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4. Catalyst-Controlled Regioselectivity in Pd-Catalyzed Aerobic Oxidative Arylation of Indoles

   https://doi.org/10.1021/acs.organomet.1c00139  

   Wang, Dian; Salazar, Chase A.; Stahl, Shannon S. (April 2021, Organometallics)

   null (Ed.)

   Pd-catalyzed C–H arylation of heteorarenes is an important and widely studied synthetic transformation; however, the regioselectivity is often substrate-controlled. Here, we report catalyst-controlled regioselectivity in the Pd-catalyzed oxidative coupling of N-(phenylsulfonyl)indoles and aryl boronic acids using O2 as the oxidant. Both C2- and C3-arylated indoles are obtained in good yield with >10:1 selectivity. A switch from C2 to C3 regioselectivity is achieved by including 4,5-diazafluoren-9-one or 2,2'-bipyrimidine as an ancillary ligand to a "ligand-free" Pd(OTs)2 catalyst system. Density functional theory calculations indicate that the switch in selectivity arises from a change in the mechanism, from a C2-selective oxidative-Heck pathway to a C3-selective C–H activation/reductive elimination pathway. 

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5. Wire like diplatinum, triplatinum, and tetraplatinum complexes featuring X[PtCCCCCCCC] _m PtX segments; iterative syntheses and functionalization for measurements of single molecule properties

   https://doi.org/10.1039/C9DT00870E  

   Zheng, Qinglin; Schneider, Jakob F.; Amini, Hashem; Hampel, Frank; Gladysz, John A. (April 2019, Dalton Transactions)

   Reaction of ( p -tol 3 P) 2 PtCl 2 and Me 3 Sn(CC) 2 SiMe 3 (1 : 1/THF/reflux) gives monosubstituted trans -Cl( p -tol 3 P) 2 Pt(CC) 2 SiMe 3 (63%), which with wet n -Bu 4 N + F − yields trans -Cl( p -tol 3 P) 2 Pt(CC) 2 H ( 2 , 96%). Hay oxidative homocoupling (O 2 /CuCl/TMEDA) gives all- trans -Cl( p -tol 3 P) 2 Pt(CC) 4 Pt(P p -tol 3 ) 2 Cl ( 3 , 68%). Reaction of 3 and Me 3 Sn(CC) 2 SiMe 3 (1 : 1/rt) affords monosubstituted all- trans -Cl( p -tol 3 P) 2 Pt(CC) 4 Pt(P p -tol 3 ) 2 (CC) 2 SiMe 3 (46%), which is converted by a similar desilylation/homocoupling sequence to all- trans -Cl[( p -tol 3 P) 2 Pt(CC) 4 ] 3 Pt(P p -tol 3 ) 2 Cl ( 7 ; 79%). Reaction of ( p -tol 3 P) 2 PtCl 2 and excess H(CC) 2 SiMe 3 (HNEt 2 /cat. CuI) gives trans -Me 3 Si(CC) 2 Pt(P p -tol 3 ) 2 (CC) 2 SiMe 3 (78%), which with wet n -Bu 4 N + F − affords trans -H(CC) 2 Pt(P p -tol 3 ) 2 (CC) 2 H (96%). Hay oxidative cross coupling with 2 (1 : 4) gives all- trans -Cl[( p -tol 3 P) 2 Pt(CC) 4 ] 2 Pt(P p -tol 3 ) 2 Cl ( 10 , 36%) along with homocoupling product 3 (33%). Reaction of 3 and Me 3 Sn(CC) 2 SiMe 3 (1 : 2/rt) yields all- trans -Me 3 Si(CC) 2 ( p -tol 3 P) 2 Pt(CC) 4 Pt(P p -tol 3 ) 2 (CC) 2 SiMe 3 ( 17 , 77%), which with wet n -Bu 4 N + F − gives all- trans -H(CC) 2 ( p -tol 3 P) 2 Pt(CC) 4 Pt(P p -tol 3 ) 2 (CC) 2 H (96%). Reaction of 3 and excess Me 3 P gives all- trans -Cl(Me 3 P) 2 Pt(CC) 4 Pt(PMe 3 ) 2 Cl ( 4 , 86%). A model reaction of trans -( p -tol)( p -tol 3 P) 2 PtCl and KSAc yields trans -( p -tol)( p -tol 3 P) 2 PtSAc ( 12 , 75%). Similar reactions of 3 , 7 , 10 , and 4 give all- trans -AcS[(R 3 P) 2 Pt(CC) 4 ] n Pt(PR 3 ) 2 SAc (76–91%). The crystal structures of 3 , 17 , and 12 are determined. The first exhibits a chlorine–chlorine distance of 17.42 Å; those in 10 and 7 are estimated as 30.3 Å and 43.1 Å. 

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