The insertion of alpha-hydroxy acids into peptide chains provides a convenient means for investigating the effects of hydrogen bond deletion on polypeptide secondary structures. The crystal structures of three oligopeptides containing L-lactic acid (Lac) residue have been determined. Peptide 1, Boc-Val-Ala-Leu-Aib-Val-Lac-Leu-Aib-Val-Ala-Leu-OMe (Boc: tert-butyloxycarbonyl; Aib: alpha- aminoiso...

Ir-catalyzed C-H borylation is found to be compatible with Boc protecting groups. Thus, pyrroles, indoles, and azaindoles can be selectively functionalized at C-H positions beta to N. The Boc group can be removed on thermolysis or left intact during subsequent transformations.

The extended BOC-PRN discriminator is shown to work efficiently for the new cosine phased binary-offset carrier BOC(f s ,f c) signals defined for global navigation satellite systems, where, n (=2f s /f c) is an arbitrary even integer. The new unambiguous code discriminator provides good multipath mitigation performance for medium delays.

Not a trace: Borylation of the nitrogen in nitrogen heterocycles or anilines provides a traceless directing group for subsequent catalytic C-H borylation. Selectivities that previously required Boc protection can be achieved; furthermore, the NBpin directing group can be installed and removed in-situ, and product yields are substantially higher. Boc=tert-butoxycarbonyl, pin=pinacolato.

somatostatin analoges labeled with different radionuclides are able used for imaging and treatment of somatostatin receptor positive tumors. in this study tyr³-octreotide protected at lysine as an analoge of somatostatin was conjugated with bifunctional chelating agent 6-boc-hydrazinopyridine-3-carboxylic acid (boc-hynic) and after deprotecting of conjugate, purification was performed with prep...

Galileo and Modernized GPS have included in their signal structures a new signal modulation: the Binary Offset Carrier (BOC), which multiplies a spreading code with a square wave sub-carrier. It creates a split spectrum with two main lobes shifted from the center frequency by sub-carrier. This modulated signal induces better tracking in white noise and better inherent multipath mitigation compa...

Aqueous in situ one-pot N-Boc-deprotection-cyclization of N alpha-Boc-dipeptidyl-tert-butyl and methyl esters under microwave irradiation afforded 2,5-diketopiperazines (DKPs) in excellent yields. This protocol is rapid, safe, environmentally friendly, and highly efficient, and showed that the tert-butoxy moiety is also an excellent leaving group for these cyclizations.

Asymmetric lithiation of substituted benzylamines, N-Boc-pyrrolidine, or N-Boc-indoline using Beak's methodology was followed by electrophilic quench with trialkylboranes. The resulting borate intermediates rearrange with concomitant C-N bond breakage to give, after oxidation, chiral secondary alcohols with high enantioselectivity.

The palladium catalyzed borylation of a Boc protected aminobromoquinoline compound with bis(pinacolato)diboron yielded a biaryl compound, resulting from cross coupling, as the major product, instead of the intended boronate, even though no strong base was used. Such results indicate that under certain conditions and with certain substrates, cross coupling can be a major problem during borylatio...