KBS51-2 - Mitsunobu reaction with KBS28 and KBS50

[KlementineJBS]

Link to HIRAC and master page #174.

HIRAC KBS48 Mitsunobu reaction on linear amines.docx

Reaction scheme

Outcome

[KlementineJBS]

1. Added KBS50 (280 mg, 0.408 mmol) and PPh3 (321.8 mg, 1.224 mmol, 3 equiv.) to a flask
2. Backfilled and evacuated x 5
3. Added KBS28 (202.3 mg, 0.898 mmol, 2.2 equiv.) dissolved in 5 mL dry THF
4. Cooled on ice for 15 minutes
5. Added DCAD (452 mg, 1.224 mmol, 3 equiv.) dissolved in 2 mL dry THF
6. left stirring at rt from 5pm

[KlementineJBS]

30.04.24

TLC at 9.30am indicated formation of product but SM not yet consumed. Heated to 40 C from then.

TLC at 3 pm was cleaner/less streaking but still showed plenty of SM. added another 115 mg of DCAD.

[KlementineJBS]

Crude LRMS and NMR

No clear sign of product (1101) but product generally doesn't ionise as well as other things.

No obvious sign of SM (686.68) or singly-alkylated product (893.92) either - only triphenylphosphine oxide adducts as usual.

KBS51-2 RM.d.zip
KBS51-2 RM.pdf

Obvious signs of desired product (peak at 4.77) but appears to be some of the singly-alkylated product as well - this seems to produce a shoulder to the 4.77 peak. No SM is evident via NMR.

nmr300_20240501_KBS51-2 RM_1.zip
KBS51-2 RM.pdf

[KlementineJBS]

01.05.24

Heated to 65 C from 11 am after TLC indicated SM was still present (despite LRMS and NMR suggesting otherwise).

[KlementineJBS]

LRMS

KBS51-2 crude.d.zip
KBS51-2 crude.pdf