Hay oxidative cross coupling (O 2 /CuCl/ TMEDA) of trans-(p-tol)(p-tol 3 P) 2 Pt(CC) 2 H (Pt T C 4 H) and excess H(CC) 2 Si-i-Pr 3 (TIPSC 4 H) gives Pt T C 8 TIPS (55%). Subsequent addition of n-Bu 4 N + F − and repetition of the Hay protocol yields Pt T C 12 TIPS (56%) and the byproduct trans-i-Pr 3 Si(CC) 2 (p-tol 3 P) 2 Pt(CC) 6 Si-i-Pr 3 (TIPSC 4 PtC 12 TIPS, 5%); another cycle gives Pt T C 16 TIPS (13%). Analogous cross couplings of trans-(C 6 F 5 )(ptol 3 P) 2 Pt(CC) 2 H (Pt F C 4 H) and excess TIPSC x H yield Pt F C 6 TIPS (x = 2, 58%) and Pt F C 8 TIPS (x = 4, 23%). Each is treated with n-Bu 4 N + F − , and repetition of the Hay protocol with TIPSC 4 H gives Pt F C 10 TIPS (58%) and Pt F C 12 TIPS (47%). When the Hay conditions are applied to Pt F C x TIPS (x = 6, 8, 10, 12) without a cross-coupling partner, homocoupling to Pt F C 2x Pt F occurs (68−99%). The reaction of trans-(p-tol 3 P) 2 PtCl 2 and TIPSC 4 H (4.5 equiv; cat. CuI, CH 2 Cl 2 /HNEt 2 ) yields TIPSC 4 PtC 4 TIPS (95%). Hay cross coupling of HC 4 PtC 4 H and excess TIPSC 4 H gives TIPSC 4 PtC 4 TIPS (6%), TIPSC 4 PtC 8 TIPS (12%), TIPSC 8 PtC 8 TIPS (10%), TIPSC 4 PtC 12 TIPS (7%), and TIPSC 8 PtC 12 TIPS (3%). Although TIPS can be a superior protecting group, it offers no advantage vs triethylsilyl in the preceding reactions. The crystal structures of

The silylated hexatriynyl complex trans-(C 6 F 5 )(ptol 3 P) 2 Pt(C�C) 3 SiEt 3 (PtC 6 TES) is converted in situ to PtC 6 H (wet n-Bu 4 N + F À , THF) and cross coupled with the diyne H(C�C) 2 SiEt 3 (HC 4 TES; CuCl/TMEDA, O 2 ) to give PtC 10 TES (71 %). This sequence is repeated twice to afford PtC 14 TES (65 %) and then PtC 18 TES (27 %). An analogous series of reactions starting with PtC 8 TES gives PtC 12 TES (60 %), then PtC 16 TES (43 %), and then PtC 20 TES (17 %). Similar cross couplings with H(C�C) 2 Si(i-Pr) 3 (HC 4 TIPS) give PtC 12 TIPS (68 %), PtC 14 TIPS (68 %), and PtC 16 TIPS (34 %). The trialkylsilyl species (up to PtC 18 TES) are converted to 3 + 2 "click" cycloadducts or 1,4-disubstituted 1,2,3-triazoles trans-(C 6 F 5 )(p-tol 3 P) 2 Pt(C�C) n-1 C K =CHN(CH 2 C 6 H 5 )N= K N (29-92 % after workups). The most general procedure involves generating the terminal polyynes PtC x H (wet n-Bu 4 N + F À , THF) in the presence of benzyl azide in DMF and aqueous CuSO 4 /ascorbic acid. All of the preceding complexes are crystallographically characterized and the structural and spectroscopic properties analyzed as a function of chain length. Two pseudopolymorphs of PtC 20 TES are obtained, both of which feature molecules with parallel sp carbon chains in a pairwise head/ tail packing motif with extensive sp/sp van der Waals contacts.

Yariv reagents are widely used tools to study plant proteoglycans known as the Arabinogalactan proteins (AGPs). Despite widespread use of the Yariv reagent in the study of AGPs and several reports of synthetic protocols, there remains a lack of a simple procedure to obtain pure Yariv reagents. We report our optimized protocols to address the purification issues faced upon synthesis of Yariv reagents. Additionally, we report challenges that make characterization difficult such as peak broadening in NMR due to Yariv-water interactions. We also show ways of processing Yariv reagents to overcome the characterization issues caused by peak broadening. File list (2) download file view on ChemRxiv YarivSynthManuscriptChemRXivSubmission.pdf (1.24 MiB) download file view on ChemRxiv YarivSynthManuscriptChemRXivSISubmission.pdf (8.91 MiB)

N-acetylglucosaminidases (GlcNAcases) play an important role in the remodeling and recycling of bacterial peptidoglycan. Inhibitors of bacterial GlcNAcases can serve as antibacterial agents and provide an opportunity for the development of new antibiotics. We report the synthesis of triazole derivatives of N-acetylglucosamine using a copper promoted azide-alkyne coupling reaction between 1-azido-N-acetylglucosamine and a small library of terminal alkynes prepared via the Ugi reaction. These compounds were evaluated for their ability to inhibit the growth of bacteria. Two compounds that show bacteriostatic activity against Bacillus were identified, with MIC values of approximately 60 μM in both cases. Bacillus subtilis cultured in the presence of sub-MIC amounts of the glycosyl triazole inhibitors exhibit an elongated phenotype characteristic of impaired cell division. This represents the first report of inhibitors of bacterial cell wall GlcNAcases that demonstrate inhibition of cell growth in whole cell assays.