Protecting-Group Economy: Route Step Simulator (2D)

Synthesis Route

Protect → Functionalize → Deprotect. The reactive site is masked before functionalization, so that step runs at high yield — but every molecule now pays for an extra two steps.

Reaction Parameters

Protected-step yield 92%

Direct chemoselectivity 55%

Protecting-group mass 100 g/mol

Live Route Metrics

Overall route yield

0.0%

Atom economy

0.0%

E-factor (kg waste / kg product)

0.00

Molecules processed / products collected

0 / 0

How it works

Green Chemistry Principle #8 says: minimize unnecessary derivatization. A protecting group (PG) temporarily masks a reactive site so a later step is cleaner and more selective — but attaching and removing it costs two extra steps, extra reagent mass, and extra chances to lose material.

Overall yield  = y1 · y2 · y3 · ...  (product of every step's yield)
Mass in        = m_core + Σ (reagent mass added at step i, scaled by the
                 fraction of the batch still present when it reaches step i)
Mass out       = (overall yield) × m_product
E-factor       = (mass in − mass out) / mass out
Atom economy   = mass out / mass in × 100%

Protecting-group route: Protect (fixed 95% yield) → Functionalize (your slider — high, because the reactive site is masked) → Deprotect (fixed 90% yield). The protecting-group mass is added at Protect and leaves as waste at Deprotect — it never appears in the product.
Direct route: Functionalize directly on the unprotected molecule at your chemoselectivity slider's yield — usually lower, because the reactive site can trigger side reactions, but there are no extra steps and no protecting-group mass to waste.
Watch the numbers cross over as you move the sliders: a very selective direct reaction can beat the protecting-group route on every metric, while a poorly selective one loses badly to it despite the extra steps.

Real-world relevance: this trade-off drives real process-chemistry decisions — pharmaceutical route selection weighs exactly this balance of step count, reagent mass and yield when scaling a synthesis from grams to tonnes.

2D view note: this is a side-view schematic of the same conveyor model as the 3D version — molecules travel left→right through the same gates, roll the same per-step yield, and feed the same mass-balance formulas above. Drag the canvas to pan, scroll/pinch to zoom.

Feed molecule Protected (PG attached) Product Waste (lost to a step)

Drag to pan · Scroll to zoom